Chemistry Topics

3-Oxapentane: Another name for Diethyl Ether.
6.022e23mol^-1: Avogadro′s number
8.314 JK^-1mol^-1: Molar gas constant.
Abegg′s Rule: This states that the difference between the maximum positive and negative valence of an element is frequently eight.
Abel Flashpoint Apparatus: A petroleum-testing apparatus for determining the flash point.
Abietic Acid: C₂₀H₃₀O₂
A resin acid that is the primary irritant in pine wood and pine resin. It is a glassy or partly crystalline yellowish solid. It belongs to the diterpene group of organic compounds. It is used in lacquers, varnishes, and soaps, and for the analysis of resins and the preparation of metal resinates.
Abietin: Abietin is a resin obtained from Strasburg turpentine or Canada balsam. It is without taste or smell, is insoluble in water, but soluble in alcohol, in strong acetic acid, and in ether.
Abietinic Acid: Another name for Abietic Acid.
Abram′s Law: A rule that the ratio of water to cement for chemical action to impart strength to concrete is 0.85:1.
ABS: Common abbreviation for Acrylonitrile Butadiene Styrene.
Absolute Vacuum: A volume which contains no matter.
Absorbed Dose: The amount of a chemical that enters the body of an exposed organism.
Absorbent: A material which, due to an affinity for certain substances, extracts one or more such substances from a liquid or gaseous medium with which it contacts.
Absorption Band: A dark band in the absorption spectrum of a substance, corresponding to a range of wavelengths for which the substance absorbs more strongly than at adjacent wavelengths.
Absorption Spectroscopy: A technique for determining the concentration and structure of a substance by measuring the amount of electromagnetic radiation the sample absorbs at various wavelengths.
Absorption Spectrum: The collection of wavelengths missing from a continuous distribution of wavelengths.
Absorptivity: The absorbance of a solution per unit of path length and per unit concentration.
Abundance Ratio: The ratio of the number of atoms of an isotope to the number of atoms of another isotope of the same element in a sample.
Ac: Actinium is a radioactive element.
Accelerating Rate Calorimetry: An important method for studying the thermal behaviour of materials.
Accelerator: A machine used to accelerate particles to high speeds.
Acceptor: An atom which is likely to take on one or more electrons when placed in a crystal.
Acenaphthene: Found in petroleum residues.
Acenaphthoquinone: C₁₂H₆O₂
A polycyclic aromatic hydrocarbon derived from naphthalene that is insoluble in water, but soluble in alcohol. It is used as an intermediate for the manufacturing of dyes, pharmaceuticals and pesticides.
Acenaphthylene: A polycyclic aromatic hydrocarbon.
Acepromazine: C₁₉H₂₂N₂OS
More commonly known as ACP it is a phenothiazine derivative antipsychotic drug.
Acetaldehyde: Formed by the oxidation of ethanol this is a colourless fruity smelling liquid that with further oxidation forms acetic acid.
Acetamide: Colourless crystalline used industrially as a solvent.
Acetaminophen: C₈H₉NO₂
More commonly known as Paracetamol, a widely used over-the-counter analgesic.
Acetanilide: Also known as Antifebrin this is a white crystalline solid.
Acetate: An ion formed by removing the acidic hydrogen of acetic acid.
Acetic acid: The acid contained in vinegar.
Acetic Anhydride: The anhydride of acetic acid, used in the manufacture of plastics.
Acetoguanamine: C₄H₇N₅
Used as a raw material for guanamine resins. It is used as a modifier and flexibilizer of formaldehyde resins and as a intermediate for pharmaceuticals.
Acetone: Also known as Dimethyl Ketone, often used as a solvent.
Acetonitrile: Also known as Methyl Cyanide, a colourless poisonous liquid, used as a solvent and in organic synthesis.
Acetophenone: Colourless sweet smelling liquid, also known as Acetylbenzene and Phenyl Methyl Ketone.
Acetyl Chloride: Also known as Ethanoyl Chloride it is a colourless pungent liquid.
Acetylbenzene: Alternative name for Acetophenone.
Acetylene: Also known as Ethyne it is made by the action of water on calcium carbide.
Acetyl-Salicyclic Acid: CH₃COOC₆H₄COOH
Commonly known as Aspirin, a white solid. Used in medicine as an antipyretic and analgesic.
Acheson Process: The Acheson process is an industrial process for the manufacture of graphite by heating coke mixed with clay.
Aciclovir: C₈H₁₁N₅O₃
One of the most commonly-used antiviral drugs, it is primarily used for the treatment of herpes simplex virus infections.
Acid: Compound that gives off H⁺ ions in solution.
Acid Air: Alternative name for Hydrogen Chloride.
Acid Anhydride: Nonmetallic oxides or organic compounds that react with water to form acids.
Acid Dissociation Constant: The equilibrium constant for the dissociation of an acid into a hydrogen ion and an anion.
Acid Error: A systematic error that occurs when glass pH electrodes are used in strongly acidic solutions.
Acid Halide: Compounds containing a carbonyl group bound to a halogen atom.
Acid Number: The quantity of base, expressed in milligrams of potassium hydroxide, that is required to neutralize the acidic constituents in 1 g of sample.
Acid of Vinegar: Another name for Acetic Acid.
Acid Rain: Rain that is weakly acidic due to pollution.
Acid Sludge: The residue left after treating petroleum oil with sulphuric acid for the removal of impurities.
Acid Treating: A refining process in which unfinished petroleum products, such as gasoline, kerosene, and lubricating oil stocks, are contacted with sulphuric acid to improve their colour, odour, and other properties.
Acid-Base Indicator: A weak acid that has acid and base forms with sharply different colours.
Acidic: Describes a solution with a high concentration of H⁺ ions.
Acidic Solution: A solution in which the hydrogen ion activity is higher than that of the hydroxide ion, when the solvent is water.
Acidulant: A substance added to food or beverages to lower pH and to impart a tart, acid taste.
Acoustic Agglomeration: High intensity sound waves are used in a fluid to group suspended particles into larger aggregates.
Acraldehyde: Alternative name for Acrolein.
Acridine: C₁₃H₉N
A colourless solid, was first isolated from coal tar. It is a raw material used for the production of dyes and some valuable drugs.
Acroleic Acid: Alternative name for Acrylic Acid.
Acrolein: C₃H₄O
the simplest unsaturated aldehyde. It has a piercing, disagreeable, acrid smell similar to that of burning fat.
Acrylamide: C₃H₅NO
A white odourless crystalline solid, soluble in water, ethanol, ether and chloroform.
Acrylic: Synthetic resin made from acrylic acid or a derivative thereof; acrylics possess the property of transparency and offer flame resistance.
Acrylic Acid: C₃H₄O₂
The simplest unsaturated carboxylic acid with a vinyl group at the a-carbon position and a carboxylic acid terminus.
Acrylic Aldehyde: Alternative name for Acrolein.
Acrylonitrile: C₃H₃N
Pungent-smelling colourless liquid that often appears yellow due to impurities. It is an important monomer for the manufacture of useful plastics.
Acrylonitrile Butadiene Styrene: A common thermoplastic used to make light, rigid, moulded products such as piping.
Acryloyl Chloride: C₃H₃ClO
A clear, light yellow, flammable liquid with an acrid smell.
Actinic: Pertaining to electromagnetic radiation capable of initiating photochemical reactions.
Actinide: Elements 89-102 are called actinides.
Actinium: A radioactive element.
Activated Carbon: Also known as Activated Charcoal.
Activated Charcoal: A porous form of carbon that acts as a powerful adsorbent.
Activated Complex: State of highest energy during a reaction.
Activation Energy: For the forward reaction is the energy required to go from reactants to the transition state.
Activation Overpotential: The overpotential which results from the restrictions imposed by the kinetics of charge transfer at an electrode.
Active Material: The material in the electrodes that takes part in the electrochemical reactions which store-deliver the electrical energy.
Active Metal: A metal that is easily oxidized in air.
Active Site: A pocket or crevice on an enzyme molecule that fits reactant molecules like a hand in a glove.
Active Transport: Energy-requiring transport of a solute across a membrane in the direction of increasing concentration.
Activity: The rate at which a collection of radioactive nuclei decay.
Activity Coefficient: The ratio of activity to concentration.
Adakane 12: Another name for Dodecane.
Adamantane: C₁₀H₁₆
A colourless, crystalline compound with a camphor-like odour. It is a cycloalkane and also the simplest diamondoid.
Addition Compound: Compound contains two or more simpler compounds that can be packed in a definite ratio into a crystal.
Addition Reaction: A chemical reaction in which two atoms or groups of atoms are added across a double bond.
Additive: A material added to another, usually in small amounts, to impart or enhance desirable properties or to suppress undesirable properties.
Adhesive Tape: A tape with a sticky substance on one side.
Adiabat: A line on an indicator diagram that represents an adiabatic process.
Adiabatic Ionization Energy: The lowest energy required to remove an electron from an atom, ion, or molecule in the gas phase.
Adipic Acid: White crystalline solid used in the manufacture of nylon.
Adipoyl Chloride: C₆H₈Cl₂O₂
A hazardous chemical that evolves HCl when reacted with water. Can be reacted with hexamethylene diamine to form nylon.
Adipoyl Dichloride: Alternative name for Adipoyl Chloride.
Adsorb: To collect molecules of a substance on a surface.
Adsorbate: A material that is adsorbed.
Adsorbent: A substance that collects molecules of another substance on its surface.
Adsorbtion Chromatography: A technique for separating or analyzing mixtures that contain at least one component that is preferentially adsorbed by the stationary phase as it moves over it.
Adsorbtion Indicator: A substance that indicates an excess of a reactant in a precipitation reaction.
Adulterants: Chemical impurities or substances that by law do not belong in a food, or pesticide.
Aeolotropy: Aeolotropy is the antithesis of isotropy.
Aeration: Preparation of a saturated solution of air gases by either spraying the solution in air or by bubbling air through it.
Aeration Tank: A chamber used to inject air into water.
Aerial Acid: An old name for carbon dioxide.
Aero Metal: A metal used in casting made from aluminium, zinc and copper.
Aerobic: Requiring or occurring in the presence of oxygen.
Aerosol: A colloid in which solid particles or liquid droplets are suspended in a gas.
Affinity: Chemical attraction.
Ag: Silver is a pure white metallic element. The best electrical conductor and used in photographic emulsions.
Ag₂S: Chemical formula for Silver Sulphide.
Agar: A gel made from seaweed used to make salt bridges.
Agent Orange: A toxic herbicide and defoliant used in the Vietnam conflict, containing 2,4,5-trichlorophen-oxyacetic acid and 2-4 dichlorophenoxyacetic acid with trace amounts of dioxin.
AgI: Chemical formula for Silver Iodide.
Agitator: A device used to cause motion in confined fluids.
AgNO₃: Silver Nitrate.
Air: The main constituents of air are Nitrogen, Oxygen, Argon, Carbon Dioxide, Neon, Helium along with a number of other trace gases.
Air of Vitriol: An old name for Sulphur Dioxide.
Air Set Cement: A cement that sets through loss of water.
Al: Aluminium is the basis for a number of alloys.
Al₂Br₆: Chemical formula for Aluminium Bromide.
Al₂I₆: Chemical formula for Aluminium Iodide.
Al₂O₃: Chemical formula for aluminium oxide.
Al₂O₃2H₂O: Chemical formula for Bauxite.
Al₂S₃: Chemical formula for Aluminium Sulphide.
Al₅Lu₃O₁₂: Chemical formula for Lutetium Aluminium Garnet.
Alabamine: The name originally proposed for Astatine.
Alanine: C₃H₇NO₂
An a-amino acid. It plays a key role in glucose-alanine cycle between tissues and liver.
Alcian Blue: C₅₆H₆₈Cl₄CuN₁₆S₄
A phthalocyanine dye that contains copper.
AlCl₃: Chemical formula for Aluminium Chloride.
Alcohol: An alcohol is an organic compound with a carbon bound to a hydroxyl group.
Aldehyde: Prepared by the oxidation of primary alcohols so that the OH group loses its hydrogen to give an oxygen joined by a double bond to a carbon atom.
Aldosterone: C₂₁H₂₈O₅
A hormone that causes the tubules of the kidneys to retain sodium and water.
AlF₃: Chemical formula for Aluminium Fluoride.
Algaecide: A chemical that when added to a solution prevents the growth of fungus and algae.
AlH₃: Chemical formula for Aluminium Hydride.
Aliphatic: An organic compound that does not contain ring structures.
Aliquot: A sample of precisely determined amount taken from a material.
Alkali: A substance that dissolves in water to give a solution of aqueous hydroxide ions that is capable of turning red litmus blue.
Alkali Metal: A metal in group IA of the periodic table that form strongly alkaline hydroxides.
Alkaline: Having a pH greater than 7.
Alkaline Air: An old name for ammonia gas.
Alkaline Earth: An oxide of an alkaline earth metal, which produces an alkaline solution in reaction with water.
Alkaline Earth Metal: A metal in group IIA of the periodic table.
Alkaline Error: A systematic error that occurs when glass electrodes are used to read the pH of an extremely alkaline solution.
Alkalinity: A measure of a material's ability to neutralize acids.
Alkaloid: A class of bitter-tasting, basic organic compounds with nitrogen-containing rings.
Alkane: A series of organic compounds with general formula C_nH_2n+2.
Alkene: A compound that consists of only carbon and hydrogen, that contains at least one carbon-carbon double bond.
Alkoxide: An ionic compound formed by removal of hydrogen ions from the hydroxyl group in an alcohol using reactive metals.
Alkyl: A molecular fragment derived from an alkane by dropping a hydrogen atom from the formula -C_nH_2n+1.
Alkyl Halide: An alkyl group attached to a halogen atom.
Alkylphenol: A family of organic compounds obtained by the alkylation of phenols.
Alkyne: A compound that consists of only carbon and hydrogen, that contains at least one carbon-carbon triple bond.
Allo-: A prefix that designates the more stable of a pair of geometric isomers.
Allobar: A form of an element that has isotopic abundances that are different from the naturally occuring form.
Allomer: Substances with different chemical composition but the same crystalline form.
Allosteric Effect: A change in the behaviour of one part of a molecule caused by a change in another part of the molecule.
Allotriomorphic Crystal: A crystal having a normal lattice structure, but with an imperfect outward shape due to the influence of its surroundings.
Allotropy: The reversible phenomenon by which certain metals may exist in more than one crystal structure.
Alloy: A metal produced by mixing other metals.
Allyl: A molecular fragment derived by removing a methyl hydrogen from propene.
Allyl Alcohol: Used in the manufacture of resins and many pharmaceuticals this is a colourless pungent liquid.
Allyl Aldehyde: Alternative name for Acrolein.
Almond Artificial Essential Oil: Alternative name for Benzaldehyde.
AlN: Chemical formula for Aluminium Nitride.
Alpha Radiation: A stream of alpha particles. Alpha rays rapidly dissipate their energy as they pass through materials, and are far less penetrating than beta particles and gamma rays.
Alternating Copolymer: A polymer, composed of two different repeating mers, in which the different mer units systematically alternate positions along the molecular chain.
Alumel: Trade name for an alloy of nickel with up to 5% aluminium, manganese and silicon, used with chromel in K-type thermocouples.
Aluminium: Basis for a number of alloys.
Aluminium Bromide: Al₂Br₆
White or very pale yellow crystalline solid.
Aluminium Bronze: A copper-aluminum alloy with high tensile strength and resistance to corrosion.
Aluminium Chloride: A chloride used as a wood preservative or catalyst.
Aluminium Fluoride: AlF₃
White crystalline solid.
Aluminium Hexabromide: Alternative name for Aluminium Bromide.
Aluminium Hexachloride: Alternative name for Aluminium Chloride.
Aluminium Hexaiodide: Alternative name for Aluminium Iodide.
Aluminium Hydride: AlH₃
White crystalline solid.
Aluminium Hydroxide: White crystalline compound that occurs naturally as the mineral gibbsite.
Aluminium Iodide: Al₂I₆
White solid.
Aluminium Nitride: AlN
Bluish white crystalline solid.
Aluminium Oxide: Al₂O₃
Alminium oxide is the most widely used oxide ceramic, either in pure form or as raw material to be mixed with other oxides.
Aluminium Production: Aluminum metal is produced by electrolysis of aluminum oxide dissolved in a high-temperature molten-salt electrolyte.
Aluminium Sulphide: Al₂S₃
Yellow or yellow grey powder.
Aluminium Tribromide: Alternative name for Aluminium Bromide.
Aluminium Trichloride: Alternative name for Aluminium Chloride.
Aluminium Triiodide: Alternative name for Aluminium Iodide.
Am: A radioactive element.
Amagat: The unit of density of a gas at stp equal to 44.614774 molm^-3.
Amalgam: An alloy that contains mercury.
American Chemical Society: Congressionally chartered independent membership organization which represents professionals at all degree levels and in all fields of chemistry and sciences that involve chemistry.
Americium: A radioactive element. Alpha particle emitter with a half life of 475 years.
Amide: The most stable of all the carbonyl functional groups.
Amine: A class of organic compounds in which one or more of the hydrogen atoms of ammonia have been replaced by other groups of atom.
Aminic Acid: Another name for Methanoic Acid.
Amino Acid: Amino acids are molecules that contain at least one amine group (-NH₂) and at least one carboxylic acid group (-COOH).
Aminoacetic Acid: A naturally occurring aliphatic amino acid, also known as glycine.
Aminobenzene: Alternative name for Aniline.
Ammine: A metal ion complex containing ammonia as a ligand.
Ammonia: Obtained from nitrogen using the Haber process and used in the manufacture of fertilizers and explosives.
Ammonium Acetate: CH₃COONH₄
Derived from the reaction of ammonia and acetic acid.
Ammonium Bicarbonate: NH₄HCO₃
Used in the food industry as a raising agent for flat baked goods.
Ammonium Carbonate: (NH₄)₂CO₃
Ammonium Chloride: NH₄Cl
A clear white water-soluble crystalline salt with a biting, slightly sour taste.
Ammonium Fluoride: NH₄F
Crystallizes as small prisms, having a sharp saline taste, and is exceedingly soluble in water.
Ammonium Hydrogen Carbonate: Alternative name for Ammonium Bicarbonate.
Ammonium Hydrogenphosphate: (NH₄)₂HPO₄
Used as a nutrient for the yeast in brewing.
Ammonium Hydroxide: A solution of ammonia in water.
Ammonium Iodide: NH₄I
Used in photographic chemicals and some medications.
Ammonium Ion: NH₄+ is a cation formed by neutralization of ammonia, which acts as a weak base.
Ammonium Nitrate: NH₄NO
The most known chemical property of ammonium nitrate is its combustability. This also makes it a very dangerous compound to work with.
Ammonium Sulphate: (NH₄)₂SO₄
Fine granulated, off white or brown crystals. There may be a slight ammonia like odour. Sulphate of ammonia is a chemical fertilizer.
Amorphography: The branch of science concerned with the determination of amorphous solid structures and their systemmatic classification.
Amorphous: Non-crystalline, without long-range order.
Amount of Substance: The SI unit of the Amount of Substance is the mole.
Amperometry: Determining the concentration of a material in a sample by measuring electric current.
Amphi-: A prefix used to name certain members of a series of geometric isomers or stereoisomers.
Amphipathic: Containing both polar and nonpolar domains.
Amphiprotic Solvent: Solvents that exhibit both acidic and basic properties.
Amphoteric: A substance that can act as either an acid or a base in a reaction.
Amyl Nitrite: C₅H₁₁NO₂
Employed medically to treat heart diseases such as angina and also to treat cyanide poisoning. It is also used as an inhalant drug that induces a brief euphoria.
Amylopectin: A form of starch made of glucose molecules linked in a branching pattern.
Amylose: A form of starch made of long, unbranched chains of -D-glucose molecules.
Amylum: Another name for starch.
Anaerobic: Occurring in the absence of air or oxygen.
Analyte: The sample constituent whose concentration is sought in a chemical analysis.
Angelic Acid: C₅H₈O₂
A monocarboxylic unsaturated organic acid found in Angelica Archangelica as well as other plants.
Angstrom: It is an old unit used for measuring the wavelength of electromagnetic radiation including visible light and X-rays.
Anhydrous: A compound with all water removed, especially water of hydration.
Aniline: Also known as Phenylamine or aminobenzene.
Anion: Ions with a negative charge.
Anisole: Also known as Methyl Phenyl Ether, an aromatic smell and used in perfumes.
Anthracene: White crystalline with a blue fluorescence used in the manufacture of dyes.
Anthracite: Type of coal with highest carbon content (86% to 98%) and thus highest heat value .
Anthracite Iron: The substance created by the smelting together of anthracite coal and iron ore.
Anthraquinone: Yellow powder derived from Anthracene and used as a dye.
Antichlor: A chemical compound that reacts with chlorine-based bleaches to stop the bleaching.
Antifebrin: Alternative name for Acetanilide.
Antimonic Chloride: Alternative name for Antimony Pentachloride.
Antimonous Chloride: Alternative name for Antimony Trichloride.
Antimonous Oxide: Alternative name for Antimony Trioxide.
Antimonselite: Alternative name for Antimony Triselenide.
Antimony: Elemental antimony is generally found in one of two allotropes and has both metallic and non-metallic properties.
Antimony Hydride: SbH₃
Poisonous gas. Also known as Stibine.
Antimony III Chloride: Alternative name for Antimony Trichloride.
Antimony Pentachloride: SbCl₅
Toxic, very corrosive and fumes in moist air. It is a reddish-yellow, oily liquid, which is hygroscopic and solidifies after moisture is absorbed.
Antimony Pentafluoride: SbF₅
Colourless, viscous liquid that is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid. Some features that give the compound scientific interest are its Lewis acidity and that it also reacts with almost all known compounds.
Antimony Pentoxide: Alternative name for Antimony V Oxide.
Antimony Perchloride: Alternative name for Antimony Pentachloride.
Antimony Quintachloride: Alternative name for Antimony Pentachloride.
Antimony Sesquioxide: Alternative name for Antimony Trioxide.
Antimony Tetroxide: Sb₂O₄, SbO₂
An inorganic compound.
Antimony Tribromide: SbBr₃
Added to polymers such as polyethylene as a fire retardant
Antimony Trichloride: SbCl₃
The soft colorless solid with a pungent odor was known to the alchemists as butter of antimony.
Antimony Trifluoride: SbF₃
A light grey crystalline material often used in dyeing and pottery.
Antimony Triiodide: SbI₃
Used as a dopant in the preparation of thermoelectric materials.
Antimony Trioxide: Sb₂O₃
The most important commercial compound of antimony.
Antimony Triselenide: Sb₂Se₃
Exists as the sulfosalt mineral antimonselite.
Antimony V Oxide: Sb₂O₅
Used as a flame retardant in ABS and other plastics, a flocculant in the production of titanium dioxide and is sometimes used in the production of glass, paint and adhesives.
Antioxidant: Compounds that slow oxidation processes that degrade foods, fuels, rubber, plastic, and other materials.
Antiozidant: Another name for Antiozonant.
Antiozonant: Substances that reverse or prevent severe oxidation by ozone.
Antipyretic: A substance that can lessen or prevent fever.
Antizonant: Substances that reverse or prevent severe oxidation by ozone.
Aprotic Solvent: A solvent that does not act as an acid or as a base.
Aqua Fortis: Ancient name for Nitric Acid, a colourless, corrosive, acid liquid that attacks most metals and other substances.
Aqua Regia: A mixture of nitric and hydrochloric acids used to dissolve gold.
Aquatic Ecotoxicity: The study of how chemicals affect the water environment and the organisms living there.
Aqueous Solubility: The maximum concentration of a chemical that will dissolve in pure water at a reference temperature.
Aqueous Solution: A solution in which water is the dissolving medium or solvent.
Ar: An inert gas that makes up about 1% of the atmosphere.
Aramid: An artificially-made organic material that forms very long and stiff fibres.
Arene: A hydrocarbon that contains at least one aromatic ring.
Argentite: Naturally occuring Silver Sulphide. An important ore of silver.
Argentum: Latin for silver, hence the symbol Ag.
Arginine: C₆H₁₄N₄O₂
A semiessential or conditionally essential amino acid in mammals.
Argon: An inert gas that makes up about 1% of the atmosphere.
Aromatic: Aromatic compounds have strong, characteristic odors.
Aromatic Compound: A compound containing an aromatic ring.
Aromatic Ring: An exceptionally stable planar ring of atoms with resonance structures that consist of alternating double and single bonds, e. g. benzene.
Arrhenius Equation: Variation of rate constant with temperature for several elementary reactions.
Arsenic: A brittle, crystalline solid which tarnishes readily in air and burns in oxygen.
Arsenic III Oxide: As₂O₃
White crystalline solid, used as an opacifier in glazes.
Arsenic V Oxide: As₂O₅
White solid.
Arsenical Bronze: An alloy of copper and arsenic in addition to other metals.
Arsenical Copper: An alloy of copper and arsenic in addition to other metals.
Arsine: Old name for Hydrogen Arsenide.
Aryl: A molecular fragment or group attached to a molecule by an atom that is on an aromatic ring.
As: A brittle, crystalline solid which tarnishes readily in air and burns in oxygen.
As₂O₃: Chemical formula for Arsenic III Oxide.
As₂O₅: Chemical formula for Arsenic V Oxide.
Asbestos: This description covers a number of fibrous silicate minerals such as calcium magnesium silicate.
Asbestosis: Fibrosis of the lungs caused by inhalation of asbestos fibres.
Ash: The mineral content of a product remaining after complete combustion.
AsH₃: Chemical formula for Hydrogen Arsenide.
Asparagine: A natural amino acid that is the amide of aspartic acid.
Aspartic Acid: A nonessential amino acid that is abundant in molasses.
Aspirin: Common name for Acetyl-Salicyclic Acid.
Assay: A quantitative determination of the metal in an ore or alloy.
Astatine: The heaviest halogen and radioactive.
Asymmetric Carbon Atom: A carbon atom that is covalently bonded to four different groups and thus may exist in two different stereospecific configurations.
At: Astatine is heaviest halogen and radioactive.
Atactic: A type of polymer chain configuration wherein side groups are randomly positioned on one side of the polymer backbone or the other.
Atom: The smallest particle of an element that can exist and still retain the ordinary chemical properties of that element.
Atom Percent: Concentration specification on the basis of the number of moles or atoms of a particular element relative to the total number of moles or atoms of all elements within an alloy.
Atomic Nucleus: A tiny, incredibly dense positively charged mass at the heart of the atom - normally abbreviated Nucleus.
Atomic Number: The atomic number (Z) of an element is the number of protons each atom of that element has in its nucleus.
Atomic Orbital: A wavefunction that describes the behavior of an electron in an atom.
Atomic Packing Factor: The fraction of the volume of a unit cell that is occupied by ′hard sphere′ atoms or ions.
Atomic Radius: One half the distance between nuclei of atoms of the same element, when the atoms are bound by a single covalent bond or are in a metallic crystal.
Atomic Theory: An explanation of chemical properties and processes that assumes that tiny particles called atoms are the ultimate building blocks of matter.
Atomic weight: The weighted average mass of the atoms in a naturally occurring element.
Au: Gold is a soft metal with a characteristic yellow colour. It is the most malleable and ductile of any element. It is unaffected by air, water, alkalis and acids.
Aufbau Principle: An approximate procedure for writing the ground state electronic configuration of atoms.
Auricupride: Cu₃Au
A natural alloy of copper and gold.
Aurum: Latin for gold, hence the symbol Au.
Autoclave: An airtight vessel constructed of thick-walled steel alloy for carrying out chemical reactions under pressure and high temperatures.
Autoigniting Propellant: Any propellant that ignites by itself without external stimulation.
Autoignition Temperature: The temperature at which combustible materials ignite spontaneously in air.
Auto-Ignition Temperature: Minimum temperature at which the vapour/air mixture over a liquid spontaneously catches fire.
Autoprotolysis: Transfer of a hydrogen ion between molecules of the same substance.
Autoxidation: Oxidation caused by exposure to air.
Auxochrome: A group or substructure in a molecule that influences the intensity of absorption of the molecule.
Avalanche: A cumulative ionization process.
Avogadros Number: N = 6.022045x10²³ mol^-1
Azeotrope: A solution that does not change composition when distilled.
Azo Compound: The azo group has the general structure Ar-N=N-Ar', where Ar and Ar' indicate substituted aromatic rings.
Azobenzene: Red insoluble crystalline powder.
B: Boron is a non-metallic element which occurs in several allotropes.
B100 Biodiesel: 100% biodiesel.
B20 Biodiesel: A blend of biodiesel fuel with petroleum-based diesel where 20% of the volume is biodiesel.
B₂O: Chemical formula for Boron Monoxide.
B₂O₃: Chemical formula for Boron Trioxide.
B₆O: Chemical formula for Boron Suboxide.
Ba: Elemental barium does not occur naturally although it has an abundance within the earth�s crust of 500 ppm.
Babbitt: A soft antifriction metal used to line bearings.
Back Titration: Determining the concentration of an analyte by reacting it with a known number of moles of excess reagent.
Background Contamination: The total of the extraneous particles which are introduced in the process of obtaining, storing, moving, transferring and analyzing a fluid sample.
BaCO₃: Chemical formula for Barium Carbonate.
Baekeland, Leo Hendrik: Belgian-born American chemist who invented Velox photographic paper and Bakelite.
Bakelite: The first industrial thermoset plastic.
Bakers Salt: Old name for Ammonium Carbonate.
Balanced Equation: A description of a chemical reaction that gives the chemical formulas of the reactants and the products of the reaction, with coefficients introduced so that the number of each type of atom and the total charge is unchanged by the reaction.
Balmer Series: A series of lines in the emission spectrum of hydrogen that involve transitions to the n=2 state from states with n>2.
Bamboo: A natural material with a great strength to weight ratio. It was used in the early construction of aircraft wings and fuselages.
Band: A set of closely spaced energy levels in an atom, molecule, or metal.
BaO: Chemical formula for Barium Oxide.
BaO₂: Chemical formula for Barium Dioxide.
Barite: Most commonly found mineral of Barium Sulphate.
Barium: Elemental barium does not occur naturally although it has an abundance within the earth�s crust of 500 ppm.
Barium Carbonate: BaCO₃
Chemical used in rat poison, bricks, ceramic glazes and cement.
Barium Dioxide: A white toxic powder obtained by heating barium oxide in air.
Barium Monoxide: An oxide of barium; a whitish toxic powder.
Barium Oxide: An oxide of barium; a whitish toxic powder.
Barium Peroxide: A white toxic powder obtained by heating barium oxide in air.
Barium Protoxide: An oxide of barium; a whitish toxic powder.
Barium Sulphate: BaSO₄
A white insoluble solid used as a pigment and filler in plastics. Most commonly found as the mineral Barite.
Barium White: An ancient name for Barium Sulphate.
Baryta: Any of several compounds of barium.
Base: Substance which gives off hydroxide ions (OH^-) in solution. In the expression x^y, x is called the base and y is the exponent.
Base Hydrolysis Constant: The equilibrium constant for the hydrolysis reaction associated with a base.
Base Number: Another name for Acid Number.
Base Oil: A liquid having a suitable boiling range and viscosity for use in lubricating oils.
BaSO₄: Chemical formula for Barium Sulphate.
Bath Metal: A cheap bronze made with 21 parts copper and 5 parts zinc. The same as pinchbeck.
Bauxite: An ore of aluminum consisting of moderately pure hydrated alumina.
Bay Salt: Alternative name for Sodium Chloride.
bcc: Abbreviation of body centred cubic. About 15% of all the elements crystallize into this structure.
Be: Beryllium is a light and lustrous metal that is resistant to attack by air or water, even at elevated temperatures
Be₃N₂: Chemical formula of Beryllium Nitride.
BeBr₂: Chemical formula of Beryllium Bromide.
BeCl₂: Chemical formula of Beryllium Chloride.
BeF₂: Chemical formula of Beryllium Fluoride.
BeI₂: Chemical formula of Beryllium Iodide.
Bell Metal: Copper tin alloy with much higher tin content than conventional bronze in order to make it hard and sonorous. It is too brittle to be used for many other applications.
Benzaldehyde: C₆H₅CHO
A colourless to yellow liquid with an almon like odour. Also known as Benzoic Aldehyde, Almond Artificial Essential Oil, Benzenecarbonal, Benzene Carboxaldehyde and Oil of Bitter Almond.
Benzene: An aromatic hydrocarbon used in the manufacture of many organic compounds.
Benzene Carboxaldehyde: Alternative name for Benzaldehyde.
Benzenecarbonal: Alternative name for Benzaldehyde.
Benzoic Acid: C₆H₅.COOH
Used as a fruit preservative. At room temperature it is a colourless solid forming glistening needles and plates, sublimes easily and is volatile in steam.
Benzoic Aldehyde: Alternative name for Benzaldehyde.
Benzoin: C₁₄H₁₂O₂
An organic compound consisting of an ethylene bridge flanked by phenyl groups and with a hydroxyl and a ketone functional group. It comes as off-white crystals, with a light camphor odor.
BeO: Chemical formula of Beryllium Oxide.
Berkelium: Element with an atomic number of 97.
Beryllia: Alternative name for Beryllium Oxide.
Beryllia Ceramic: Alternative name for Beryllium Oxide.
Beryllium: Beryllium is a light and lustrous metal that is resistant to attack by air or water, even at elevated temperatures
Beryllium Bromide: BeBr₂
Hygroscopic and dissolves readily in water.
Beryllium Chloride: BeCl₂
White crystalline substance that reacts vigorously and exothermically with water with the evolution of acidic, steamy hydrogen chloride gas. It attacks many metals in presence of water.
Beryllium Copper: Heat treatable copper-beryllium alloy of high strength and hardness. Used for making springs and non-sparking tools.
Beryllium Fluoride: BeF₂
A crystalline solid, the principal precursor for the manufacture of beryllium metal.
Beryllium Hydroxide: Be(OH)₂
A white solid. One of only a few amphoteric metal hydroxides.
Beryllium Iodide: BeI₂
Colourless needle-like crystals that are very hygroscopic and reacts violently with water, forming hydroiodic acid.
Beryllium Nitride: Be₃N₂
A common component of refractory ceramics.
Beryllium Oxide: BeO
White crystalline oxide that when sintered is very stable and has ceramic characteristics.
Beryllium Telluride: BeTe
A crystalline solid that is a semiconductor with a large energy gap of around 3 eV.
BeTe: Chemical formula of Beryllium Telluride.
Bi: Bismuth is a brittle metal which is silvery in colour with a pink tinge.
Bicarbonate of Ammonia: Alternative name for Ammonium Bicarbonate.
Bidentate: A ligand that has two "teeth" or atoms that coordinate directly to the central atom in a complex.
Biethylene: Another name for 1,3-Butadiene.
Bifunctional Monomer: A monomer unit that has two active bonding positions.
Bihexyl: Another name for Dodecane.
Billon: An alloy of copper and silver with more than 50% copper.
Bimolecular Step: Two species are reacting and form the transition state.
Binary Compound: A compound that contains two different elements.
Biochemical Conversion: The use of enzymes and catalysts to change biological substances chemically to produce other products.
Biochemistry: The chemistry of living things, including the structure and function of biological molecules and the mechanism and products of their reactions.
Biocide: Chemical substance capable of killing living organisms, usually in a selective way.
Biodiesel: Diesel fuel derived from renewable lipid feedstocks, such as vegetable oils and animal fats.
Biodiesel B100: 100% (neat) biodiesel. The mono alkyl esters of long chain fatty acids derived from renewable lipid feedstocks, such as vegetable oils and animal fats, diesel engines
Biodiesel B20: A blend of biodiesel fuel with petroleum-based diesel where 20% of the volume is biodiesel.
Biosensor: Either a sensor to detect a biological substance or a sensor which incorporates the use of biological molecules such as antibodies or enzymes.
Biotin: Commonly known as vitamin H.
Biphenyl: C₁₂H₁₀
Notable as a starting material for the production of PCBs, which were once widely used as dielectric fluids and heat transfer agents.
Bischofite: Natural occuring mineral of Magnesium Chloride.
Bismuth: Bismuth is a brittle metal which is silvery in colour with a pink tinge.
Bismuth Chloride: BiCl₃
A water soluble crystalline source of bismuth.
Bismuth Germanate: Bi₄Ge₃O₁₂
Used in detectors in particle physics and nuclear medicine.
Bismuth Subcarbonate: Bi₂O₂(CO₃)
Chemical compound of bismuth containing both oxide and carbonate.
Bismuth Subgallate: C₇H₅BiO₆
Used in medicine as an internal deodorant.
Bitter Salts: Common name for Magnesium Sulphate.
Bittern: Waste solution of magnesium salts and bromides from the preparation of salt from sea-water by evaporation.
Bitumen: A name used to describe many different mixtures of hydrocarbons.
Bk: Berkelium is an element with an atomic number of 97.
Black, Joseph: Scottish chemist who laid the foundations for thermodynamics.
Black Lead: Natural crystalline form of carbon, used to make vessels that resist high temperatures and in making pencils.
Blackett, Patrick Maynard Stuart: English chemist who developed the cloud chamber.
Blast Furnace: A vertical shaft type furnace used for reducing iron ore to pig iron when cast or hot metal for further melting. This product is used in an open hearth or basic oxygen furnaces for production of steel.
Bleach: A dilute solution of sodium hypochlorite or calcium hypochlorite which kills bacteria and destroys coloured organic materials by oxidizing them.
Blind Reference Oil: A reference oil, the identity of which is unknown by the test facility.
Block Copolymer: A linear copolymer in which identical mer units are clustered in blocks along the molecular chain.
Blue Vitriol: An old fashioned name for hydrated copper sulphate.
BN: Chemical formula for Boron Nitride.
Body Centred Cubic: About 15% of elements crystallize with a body centred cubic structure.
Boiling Point: The temperature at which the vapour pressure of a liquid is equal to the external pressure on the liquid.
Boiling Point Elevation: The boiling point of a solution is higher than the boiling point of the pure solvent.
Boiling Range: For a mixture of substances, such as a petroleum fraction, the temperature interval between the initial and final boiling points.
Bond Energy: The energy required to break a given chemical bond.
Bond Length: The average distance between the nuclei of two bonded atoms in a stable molecule.
Bond Order: In Lewis structures, the number of electron pairs shared by two atoms.
Bond Strength: Some measure of how difficult it is to break a chemical bond, for example, a bond energy or a bond enthalpy.
Bonding Energy: The energy required to separate two atoms that are chemically bonded to each other.
Bone: Primarily based on phosphate and carbonate.
Bone Black: An impure animal charcoal prepared from bones and blood.
Boron: Boron is a non-metallic element which occurs in several allotropes.
Boron Monoxide: B₂O
Chemical compound of boron and oxygen.
Boron Nitride: BN
Excellent thermal and chemical stability, boron nitride ceramics are traditionally used as parts of high-temperature equipment.
Boron Suboxide: B₆O
Due to its short interatomic bond lengths and strongly covalent character, it displays a range of outstanding physical and chemical properties such as great hardness, low mass density, high thermal conductivity, high chemical inertness, and excellent wear resistance.
Boron Trioxide: B₂O₃
White glassy solid almost always found as the vitreous form; however, it can be crystallized after extensive annealing.
Boyle, Robert: Known for that scientific law named after him.
bp: Abbreviation of boiling point, the temperature at which the vapour pressure of a liquid is equal to the external pressure on the liquid.
Bq: An abbreviation of Becquerel. One Becquerel is that quantity of a radioactive material that will have 1 transformations in one second.
Br: Bromine is an element in the halogen group.
Bragg′s Law: A relationship that stipulates the condition for diffraction by a set of crystallographic planes.
Brakish Water: Water having less salt than sea water, but undrinkable, having salinity values ranging from about 0.5 to 17 parts per thousand.
Branched Polymer: A polymer having a molecular structure of secondary chains that extend from the primary chains.
Brimstone: Ancient name for Sulphur.
Brominated Flame Retardants: A group of chemicals used in plastics and textiles to give flame retardant properties.
Bromine: An element in the halogen group.
Bromoethane: C₂H₅Br
A colourless volatile liquid that has an ether-like odour.
Bromomethane: CH₃Br
A colorless, nonflammable gas with no distinctive smell.
Br�sted Acid: A material that gives up hydrogen ions in a chemical reaction.
Br�sted Base: A material that accepts hydrogen ions in a chemical reaction.
BTX: Refers to the group of aromatic hydrocarbons: benzene, toluene and xylene.
Buckminsterfullerene: C60
A form of carbon consisting of 60 carbon atoms bound together to make a roughly spherical "buckyball".
Buckyball: A form of carbon consisting of 60 carbon atoms bound together to make a roughly spherical buckyball.
Buffer Solutions: Solutions that resist changes in their pH, even when small amounts of acid or base are added.
Bunsen Burner: A gas burner with adjustable air intake, commonly used in laboratories.
Bunsen, Robert Wilhelm: Introduced the bunsen burner.
Buret: A cylindrical glass tube closed by a stopcock on one end and open on the other, with volume gradations marked on the barrel of the tube, used to precisely dispense a measured amount of a liquid.
Burette: A cylindrical glass tube closed by a stopcock on one end and open on the other, with volume gradations marked on the barrel of the tube, used to precisely dispense a measured amount of a liquid.
Burgess Vector: A vector that denotes the magnitude and direction of lattice distortion associated with a dislocation.
Butadiene: C₄H₆
An important industrial chemical used as a monomer in the production of synthetic rubber.
Butane: C₄H₁₀
An alkane hydrocarbon. Commonly used in compressed form for portable heaters and cookers.
Butanol: An alcohol containing four carbon atoms.
Butene: C₄H₈
A colourless gas that is present in crude oil as a minor constituent in quantities that are too small for viable extraction.
Butter of Antimony: Alternative name for Antimony Trichloride.
Butter of Zinc: An old name for Zinc Chloride.
Butyl Alcohol: Alternative name for Butanol.
Butylene: Another name for Butene.
C: Carbon occurs naturally in two allotropic forms, namely graphite and diamond.
C₁₀H₁₆: Chemical formula for Adamantane.
C₁₀H₁₆N₂O₈: Chemical formula for Ethylenediaminetetraacetic Acid.
C₁₀H₂₂: Chemical formula for Decane.
C₁₀H₆MgN₄O₈: Chemical formula for Magnesium Orotate.
C₁₁H₂₄: Chemical formula for Undecane.
C₁₂H₁₀: Chemical formula of Acenaphthene.
C₁₂H₁₀N₂: Chemical formula for Azobenzene.
C₁₂H₂₆: Chemical formula for Dodecane.
C₁₂H₆O₂: Chemical formula for Acenaphthoquinone.
C₁₂H₈: Chemical formula for Acenaphthylene.
C₁₃H₉N: Chemical formula for Acridine.
C₁₄H₁₀: Chemical formula for Anthracene.
C₁₄H₁₀MgO₄: Chemical formula for Magnesium Benzoate.
C₁₄H₁₂O₂: Chemical formula for Benzoin.
C₁₄H₈O: Chemical formula for Anthraquinone.
C₁₅H₂₁NO₆: Chemical formula for Domoic Acid.
C₁₅H₂₄: Chemical formula for Zingiberene.
C₁₆H₃₂: Chemical formula for Cetene.
C₁₉H₂₂N₂OS: Chemical formula for Acepromazine.
C₂₀H₃₀O₂: Chemical formula for Abietic Acid.
C₂₁H₂₈O₅: Chemical formula for Aldosterone.
C₂H₂: Chemical formula for Acetylene.
C₂H₃N: Chemical formula for Acetonitrile.
C₂H₃OCl: Chemical formula for Acetyl Chloride.
C₂H₄O: Chemical formula for Acetaldehyde.
C₂H₅Br: Chemical formula for Bromoethane.
C₂H₅Cl: Chemical formula for Chloroethane.
C₂H₅OH: Chemical formula for ethanol.
C₂H₅ON: Chemical formula for Acetamide.
C₂H₆: Chemical formula for Ethane.
C₂HCl₃: Chemical formula for Trichlorethene.
C₂N₂: Chemical formula for Cyanogen.
C₃₆H₇₀MgO₄: Chemical formula for Magnesium Stearate.
C₃H₃ClO: Chemical formula for Acryloyl Chloride.
C₃H₃N: Chemical formula for Acrylonitrile.
C₃H₄O: Chemical formula for Acrolein.
C₃H₄O₂: Chemical formula for Acrylic Acid.
C₃H₅N₃O₉: Chemical formula for Nitroglycerine.
C₃H₅NO: Chemical formula for Acrylamide.
C₃H₆: Chemical formula for Propene.
C₃H₆O: Chemical formula for acetone.
C₃H₆O₂: Chemical formula for Methyl Acetate.
C₃H₆O₃: Chemical formula for Lactic Acid.
C₃H₇NO₂: Chemical formula for Alanine.
C₃H₇NO₂S: Formula for Cystine
C₃H₇OH: Chemical formula for Propanol.
C₃H₈: Chemical formula for Propane.
C₃H₈O₃: Chemical formula for Glycerol.
C₄H₁₀: Chemical formula for butane.
C₄H₁₀O: Chemical formula for Diethyl Ether.
C₄H₁₂N₂: Chemical formula for Putrescine.
C₄H₆O₃: Chemical formula for Acetic Anhydride.
C₄H₆O₅: Another name for Hydroxybutanedioic Acid.
C₄H₈: Chemical formula for Butene.
C₄H₉OH: Chemical formula for Butanol.
C₅₆H₆₈Cl₄CuN₁₆S₄: Chemical formula for Alcian Blue.
C₅H₁₁NO₂: Chemical formula for Amyl Nitrite.
C₅H₁₁OH: Chemical formula for Pentanol.
C₅H₁₂: Chemical formula for pentane.
C₅H₈NNaO₄: Chemical formula for Monosodium Glutamate.
C₅H₈O₂: Chemical formula for Angelic Acid.
C60: Buckminsterfullerene formed from 60 carbon atoms.
C₆H₁₀O₄: Chemical formula for Adipic Acid.
C₆H₁₂N₂O₄S₂: Chemical formula for Cysteine.
C₆H₁₃NO₂: Chemical formula for Isoleucine.
C₆H₁₄: Chemical formula for Hexane.
C₆H₁₄N₄O₂: Chemical formula for Arginine.
C₆H₅CHO: Chemical formula for Benzaldehyde.
C₆H₅Cl: Chemical formula for Chlorobenzene.
C₆H₅ COOH: Chemical formula for Benzoic Acid.
C₆H₅NO₂: Chemical formula for nitrobenzene.
C₆H₅OH: Chemical formula for Phenol.
C₆H₆: Chemical formula for benzene, an aromatic hydrocarbon used in the manufacture of many organic compounds.
C₆H₆O: The chemical formula for phenol, a strong disinfectant.
C₆H₆O₇Mg: Chemical formula for Magnesium Citrate.
C₆H₇N: Chemical formula for Aniline.
C₆H₈Cl₂O₂: Chemical formula for Adipoyl Chloride.
C₆H₈O₇: Chemical formula for Citric Acid.
C₆O₆Mo: Chemical formula for Molybdenum Hexacarbonyl.
C₇H₁₆: Chemical formula for heptane.
C₇H₅N₃O₆: Chemical formula for Trinitrotoluene.
C₇H₈: Chemical formula for toluene.
C₇H₈O: Chemical formula for Anisole.
C₈H₁₀N₄O₂: A substance found in tea, coffee, and cola that acts as a stimulant.
C₈H₁₁N₅O₃: Chemical formula for Aciclovir.
C₈H₁₂MgN₂O₈: Chemical formula for Magnesium Aspartate.
C₈H₁₈: Flammable liquid compounds found in petroleum and natural gas.
C₈H₈O: Chemical formula for Acetophenone.
C₈H₉NO₂: Chemical formula for Acetaminophen.
C₈H₉ON: Chemical formula for Acetanilide.
C₉H₂₀: Chemical formula for Nonane.
Ca: Calcium is one of the most abundant metal elements on Earth (41000 ppm).
CaC₂: Chemical formula for Calcium Carbide.
CaCl₂: Chemical formula for Calcium Chloride
CaCO₃: Chemical formula for Calcium Carbonate.
Cadmium: A white metallic element.
Cadmium Oxide: Commonly used in glasses, plastics, ceramics and porcelain enamels as a coloring agent for reds, oranges, and yellows.
Cadmium Sulphate: CdSO₄
Colourless, odourless crystals that are freely soluble.
Cadmium Sulphide: CdS
Found as the mineral greenockite, it is used together with selenium to produce strong reds and yellows.
Caesium: A soft metal which is often liquid at room temperature due to its relatively low melting point (28.5�C).
Caesium Bromide: CsBr
White crystalline solid.
Caesium Chloride: CsCl
White crystalline solid.
Caesium Fluoride: CsF
White crystalline solid.
Caesium Hydride: CsH
White crystalline solid.
Caesium Iodide: CsI
White crystalline solid.
Caesium Oxide: Cs₂O
Yellow to orange crystalline solid.
Caesium Peroxide: Cs₂O₂
Yellow crystalline solid.
Caesium Sulphide: Cs₂S
White to pale yellow crystalline solid.
Caesium Superoxide: CsO₂
Yellow to orange crystalline solid.
Caffeine: A substance found in tea, coffee, and cola that acts as a stimulant. It is extremely soluble in supercritical fluid carbon dioxide and somewhat soluble in water; aqueous solutions of caffeine quickly break down.
Calamine Brass: Brass produced by a particular alloying technique using calamine (a zinc ore) rather than metallic zinc.
Calcination: A high-temperature reaction whereby one solid material dissociates to form a gas and another solid.
Calcium: One of the most abundant metal elements on Earth (41000 ppm).
Calcium Carbide: CaC₂
Usually formed by fusing lime and hard coal in a furnace.
Calcium Carbonate: CaCO₃
A white insoluble solid, occuring naturally as chalk, limestone, marble and calcite.
Calcium Chloride: CaCl₂
Absorbs moisture from the atmosphere and is used for drying gases.
Calcium Hypochlorite: CaCl(OCl)
More commonly known as bleaching powder.
Calcium Magnesium Acetate: Used as an alternative to road salt.
Calcium Oxide: CaO
Also know as Quicklime.
Calcium Sulphate: CaSO₄
Used to make plaster of paris and plaster.
Californium: A man-made element with an atomic number of 98.
Calomel: Another name for Mercury I Chloride.
Calutron: A device that separates isotopes by ionizing the sample.
CaO: Chemical formula for Calcium Oxide.
Carbide: The old abbreviated name for calcium carbide.
Carbohydrate: A class of organic compounds including sugars and starches.
Carbolic Acid: Also known as phenol, it is used as a strong disinfectant.
Carbon: Occurs naturally in two allotropic forms, namely graphite and diamond.
Carbon Bisulphide: Alternative name for Carbon Disulphide.
Carbon Dioxide: A heavy, colourless gas that is the fourth most abundant constituent of dry air, comprising 0.033% of the total.
Carbon Disulphide: Also known as Carbon Bisulphide used as a solvent in the vulcanization of rubber.
Carbon Hydride Nitride: Alternative name for Hydrogen Cyanide.
Carbon Monoxide: A colourless gas that is very poisonous as it combines with the haemoglobin in blood forming a stable compound so reducing the ability to carry oxygen.
Carbon Residue: The carbon remaining after evaporating off the volatile portion of a fuel or lubricating oil by heating it in the absence of air under controlled test conditions.
Carbon Tetrachloride: Colourless liquid with a sweet smell used as a solvent.
Carbon Tetrafluoride: Alternative name for Tetrafluoromethane.
Carbonado: Carbon that has metamorphosed into its diamond phase but remains black.
Carbonate: An inorganic ion with a charge of -2, containing carbon bound directly to three oxygens in a in a flat triangular arrangement.
Carbonate Water Hardness: Water hardness due to the presence of calcium and magnesium carbonates and bicarbonates.
Carbonic Acid: H₂CO₃
A weak acid formed by carbon dioxide dissolved in water.
Carbonic Oxide: Old name for Carbon Monoxide.
Carbonyl: A divalent group consisting of a carbon atom with a double-bond to oxygen.
Carboxamide: NH₂CONH₂
More commonly known as Urea, the main nitrogenous excretion of most animals. It has the distinction of being the first organic compound to have been made in a laboratory (1828). Urea is used in the manufacture of ammonia and carbon dioxide.
Carboxylic Acid: A compound with molecules containing a carboxylic acid group -COOH.
Carboy: A very large bottle.
Carburetted Hydrogen: Old name for Methane.
Carcinogens: Substances known to cause cancer.
Carotene: Carotene is an unsaturated hydrocarbon pigment found in many plants. Carotene is the basic building block of vitamin A.
CaSO₄: Chemical formula for Calcium Sulphate.
Cassiterite: Dark coloured mineral that is an important ore of Tin.
Catalyst: Substance that speeds up a chemical process without actually changing the products of reaction.
Catalytic Converter: An air pollution abatement device that removes pollutants from motor vehicle exhaust, either by oxidizing them into carbon dioxide and water or reducing them to nitrogen.
Catalytic Cracking: The use of a catalyst to break down the molecules of the high boiling temperature fractions of crude oil.
Cathode: Electrode where electrons are gained (reduction) in redox reactions.
Cathodic Protection: A means of corrosion prevention.
Cations: Ion with a positive charge.
Cauk: Old name for Barium Sulphate.
Caustic: A substance that causes corrosion.
Caustic Potash: Old fashioned name for Potassium Hydroxide.
Caustic Soda: Alternative name for Sodium Hydroxide.
Cavendish, Henry: English physicist and chemist, discovered hydrogen.
Cawk: Old name for Barium Sulphate.
CCl₃F: Chemical formula for Trichlorofluoromethane.
CCl₄: Chemical formula for Carbon Tetrachloride.
Cd: Cadmium is a white metallic element.
CdS: Chemical formula for cadmium sulphide.
CdSO₄: Chemical formula for Cadmium Sulphate.
Ce: Cerium is a reactive grey metal and is one of the most abundant of the lanthanide group of metals.
Ce₂O₃: Chemical formula for Cerium III Oxide.
CeCl₃: Chemical formula for Cerium III Chloride.
Cellophane: Cellophane is a thin, transparent, waterproof, protective film that is used in many types of packaging.
Cellulose: A polysaccharide made of linked glucose molecules that strengthens the cell walls of most plants.
Cellulose Acetate: Used as a film base in photography, and as a component in some adhesives. It is also used as a synthetic fibre.
Cellulosic Ethanol: Ethanol made from agricultural refuse, grass, wood, municipal waste and a variety of feedstock, which is less expensive and more available than just corn.
Cement: A substance that can be used to build together aggregates of sand or stone into a cohesive structure. May be a single compound or a mixture. May be hydraulic set, air set or chemical set.
CeO₂: Chemical formula for Cerium Oxide.
Ceramic: Inorganic, nonmetalllic products for which the interatomic bonding is predominantly ionic.
Ceric Oxide: Another name for Cerium Oxide.
Cerium: A reactive grey metal and is one of the most abundant of the lanthanide group of metals.
Cerium III Chloride: CeCl₃
A white hygroscopic solid; It rapidly absorbs water on exposure to moist air to form a hydrate.
Cerium III Oxide: Ce₂O₃
Gold-yellow coloured oxide of rare earth metal cerium.
Cerium IV Sulphate: Ce(SO₄)₂
Yellow to yellow/orange chemical compound that is a strong oxidizer.
Cerium Oxide: CeO₂
The oxide of the rare earth element cerium. Cerium oxide usually appears as a yellow powder. It is insoluble in water and moderately soluble in strong mineral acids. Used alone or together with other substances as a polishing agent for glass.
Cermet: A composite material consisting of a combination of ceramic and metallic materials.
Cerous Chloride: Chemical formula for Cerium III Chloride.
Cerussite: Mineral form of Lead II Carbonate.
Cetane Index: A calculated value, derived from fuel density and volatility, giving a reasonably close approximation to cetane number.
Cetane Number: A percentage indicating the ignition quality of diesel fuels.
Cetene: C₁₆H₃₂
An oily hydrocarbon of the ethylene series, obtained from spermaceti.
Cf: Californium is a man-made element with an atomic number of 98.
CF₄: Chemical formula for Tetrafluoromethane.
CH₂Cl₂: Chemical formula for Dichloromethane.
CH₂O₂: Chemical formula for for Methanoic Acid.
CH₃Br: Chemical formula for Bromomethane.
CH₃CH₂NH₂: Chemical formula for Ethylamine.
CH₃Cl: Chemical formula for Chloromethane.
CH₃COOC₆H₄COOH: Chemical formula for Acetyl-Salicyclic Acid.
CH₃COOCH₂CH₃: Chemical formula for Ethyl Acetate.
CH₃COONH₄: Chemical formula for Ammonium Acetate.
CH3OCH3: Chemical formula for Dimethyl Ether.
CH₃OH: A colourless liquid also known as methyl alcohol.
CH₄: The chemical formula for methane, the first alkane.
CH₄O: Chemical formula for Methyl Alcohol.
Chalk: Common form of Calcium Carbonate.
Change of State: The change in a substance between solid and liquid or between liquid and gas.
Characteristic X-ray: An X-ray having a unique energy that is emitted by an atom during its de-energization after ionization of one of its electrons.
Charcoal: Used to describe different forms of carbon. Formed by heating vegetable or animal matter in the absence of air.
Charge Transfer Reaction: A chemical reaction where an electrical charge is transferred from one reactant to another.
Charged: Possessing a net negative or positive charge.
CHCl₃: Chemical formula for chloroform.
Chelate: A stable complex of a metal with one or more polydentate ligands.
Chelating Agent: A ligand that binds to a metal using more than one atom; a polydentate ligand.
Chemical: 1. of or pertaining to chemistry. 2. a substance.
Chemical Analysis: Determination of the composition of a sample.
Chemical Bond: A chemical bond is a strong attraction between two or more atoms.
Chemical Change: A chemical change is a dissociation, recombination, or rearrangement of atoms.
Chemical Differentiation: The separation of different elements, often heavier elements from lighter elements, as a consequence of different chemical reactions.
Chemical Energy: Energy stored in the bonds of atoms and molecules eg coal, petrol, biomass.
Chemical Equation: A compact notation for describing a chemical change.
Chemical Formula: A representation of a chemical substance that uses chemical symbols to denote the constituent atoms, and subscripts to indicate the relative numbers of atoms of each type.
Chemical Property: Measurement of a chemical property involves a chemical change.
Chemical Reaction: A process that leads to the transformation of one set of chemical substances to another.
Chemical Set Cement: A cement that sets through reaction or precipitation.
Chemical Stability: The tendency of a substance or mixture to resist chemical change.
Chemical Symbols: Each element has it′s own symbol and these together build up the chemical symbols.
Chemiluminescence: A chemical reaction that releases energy as electromagnetic radiation.
Chile Nitre: Another name for Sodium Nitrate.
Chinese Silver: An alloy used for jewellery, 58% copper, 17.5% zinc, 11.5% nickel, 11% cobalt, and 2% silver.
Chinese White: The old name for Zinc Oxide.
Chiral Centre: An atom in a molecule that causes chirality, usually an atom that is bound to four different groups.
Chlorane: Alternative name for Hydrogen Chloride.
Chlorination: The application of chlorine to drinking water, sewage, or industrial waste to disinfect or to oxidize undesirable compounds.
Chlorine: A greenish yellow gas and second in the halogen group.
Chlorobenzene: C₆H₅Cl
Colourless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.
Chloroethane: C₂H₅Cl
A colorless, flammable gas or refrigerated liquid with a faintly sweet odour.
Chloroform: Volatile colourless heavy liquid used as an anaesthetic and solvent.
Chlorohydric Acid: Alternative name for Hydrochloric Acid.
Chloromethane: CH₃Cl
A colourless extremely flammable gas with a slightly sweet odor. Once commonly used as a refrigerant.
Chromatography: A method for separating mixtures based on differences in the speed at which they migrate over or through a stationary phase.
Chrome Green: Alternative name for Chromium Oxide.
Chrome Yellow: An old name for Lead II Chromate IV.
Chromel: An alloy of nickel with about 10% chromium, used with Alumel in K-type thermocouples.
Chromic Oxide: Alternative name for Chromium Oxide.
Chromium: A bright, blue/white metal with excellent corrosion resistance.
Chromium Dioxide: CrO₂
A black crystalline solid.
Chromium IV Oxide: Alternative name for Chromium Dioxide.
Chromium Oxide: Cr₂O₃
The only stable oxide of chromium. It is a bright to dark green crystalline powder insoluble in alkalis and acids.
Chromium VI Oxide: CrO₃
Highly poisonous.
Chromophore: A group or substructure on a molecule that is responsible for the absorption of light.
Citric Acid: C₆H₈O₇
Natural preservative and also used to add an acidic, or sour, taste to foods and soft drinks.
Cl: Chlorine is a greenish yellow gas and second in the halogen group.
Cl₁₀Mo₂: Chemical formula for Molybdenum V Chloride.
Clausius-Clapeyron Equation: Predicts the temperature dependence of vapour pressures of pure liquids or solids.
Cm: Curium is a man-made radioactive element.
CNG: Abbreviation of Compressed Natural Gas.
Co: Cobalt is a hard, grey metal which is ferromagnetic.
CO: Chemical formula for Carbon Monoxide.
CO₂: Chemical formula for Carbon Dioxide.
Co₂O₃: Chemical formula for Cobalt III Oxide.
Coal: A fossil fuel which is made mostly of carbon. It is formed from plants that grew around 150 million years ago.
Coal Tar: A dark brown to black cementitious material produced by the destructive distillation of bituminous coal.
Cobalt: A hard, grey metal which is ferromagnetic.
Cobalt Dichloride: Alternative name for Cobalt II Chloride.
Cobalt II Bromide: CoBr₂
Green crystals, used as a catalyst in the oxidation of some organic compounds.
Cobalt II Chloride: CoCl₂
Used as an indicator for water as there is a dramatic colour change from CoCl₂ which is blue to CoCl₂�6H₂O which is a deep rose colour.
Cobalt II Nitrate: Co(NO₃)₂
A red crystalline solid with high solubility of cobalt nitrate makes it a common source of cobalt in metal-organic frameworks and polymers. Deliquescent in moist air.
Cobalt II Oxide: CoO
Olive green to red crystals or greyish or black powder used in ceramics to create blue coloured glazes.
Cobalt III Oxide: Co₂O₃
A black substance obtained by adding cobalt II nitrate to an aqueous solution of sodium hypochlorite.
Cobalt Monoxide: Alternative name for Cobalt II Oxide.
Cobalt Sesquioxide: Alternative name for Cobalt III Oxide.
Cobalt Trioxide: Alternative name for Cobalt III Oxide.
Cobaltic Oxide: Alternative name for Cobalt III Oxide.
Cobaltous Chloride: Alternative name for Cobalt II Chloride.
Cobaltous Monoxide: Alternative name for Cobalt II Oxide.
Cobaltous Nitrate: Alternative name for Cobalt II Nitrate.
Cobaltous Oxide: Alternative name for Cobalt II Oxide.
CoBr₂: Chemical formula for Cobalt II Bromide.
CoCl₂: Chemical formula for Cobalt II Chloride.
Cohesion: Attraction between like molecules.
Coke: A hard, dry substance containing carbon that is produced by heating bituminous coal to a very high temperature in the absence of air.
Colligative Properties: Properties of a solution that depend only on the number of particles dissolved in it, not the properties of the particles themselves.
Collision Frequency: The average number of collisions that a molecule undergoes each second.
Collision Theory: A theory that explains reaction rates in terms of collisions between reactant molecules.
Colloid: A heterogeneous mixture composed of tiny particles suspended in another material.
Colourimetry: A method for chemical analysis that relates colour intensity to the concentration of analyte.
Columbium: A name sometimes given to Niobium, a platinum-gray, ductile metal with brilliant luster that is used in alloys, especially stainless steels.
Column Chromatography: A method for separating mixtures.
Columnar Structure: Coarse structure of parallel columns of grains.
Combination Reaction: A reaction in which two or more substances are chemically bonded together to produce a product.
Combustible: Substance that can easily be set on fire and that will burn readily or quickly. Flammable.
Combustion: A chemical reaction between a fuel and an oxidizing agent that produces heat.
Combustion Reaction: The vigorous and exothermic reaction that takes place between certain substances, particularly organic compounds, and oxygen.
Common Salt: Sodium Chloride.
Complete Combustion: A combustion reaction that converts all of the fuel′s carbon, hydrogen, sulphur, and nitrogen into carbon dioxide, water, sulphur dioxide, and N₂ respectively.
Complete Ionic Equation: A balanced equation that describes a reaction occurring in solution, in which all strong electrolytes are written as dissociated ions.
Complex Compound: Compound contains two or more simpler compounds that can be packed in a definite ratio into a crystal.
Complex Ion: An ion formed by combination of simpler ions or molecules.
Complexing Agent: A ligand that binds to a metal ion to form a complex.
Complexometric Titration: A titration based on a reaction between a ligand and a metal ion to form a complex.
Component: An element or chemical compound that helps make up a material system.
Compound: A pure substance which contains two or more different elements chemically bonded together in stoichiometric proportions.
Compressed Natural Gas: Natural gas compressed to a volume and density that is practical as a portable fuel supply.
Computational Chemistry: A branch of chemistry concerned with the prediction or simulation of chemical properties, structures, or processes using numerical techniques.
CoN₂O₆: Chemical formula for Cobalt II Nitrate.
Concentrate: To increase the amount of substance present in a unit amount of mixture.
Concentrated: Having a relatively large amount of substance present in a unit amount of mixture.
Concentration: The amount of substance in a specified space.
Concentration Cell: A voltaic cell in which both compartments contain the same components, but at different concentrations.
Concrete: Building material made from cement, sand, stone and water.
Condensation Polymerization: The formation of polymers by an intermolecular reaction involving at least two monomer species.
Conformers: Molecular arrangements that differ only by rotations around single bonds.
Congener: Elements belonging to the same group on the periodic table.
Congruent Transformation: A transformation of one phase to another that does not involve any change in composition.
Conjugate Acid: A substance which can lose a H⁺ ion to form a base.
Conjugate Base: A substance which can gain a H⁺ ion to form an acid.
Conjugated Redox Pair: An electron donor and its corresponding electron acceptor form.
Constantan: An alloy of 40% nickel and 60% copper, with a high volume resistivity and almost negligible temperature coefficient. Used with copper in T-type thermocouples.
Contact Adsorption: Adsorption with the adsorbed molecule or ion being in direct contact with the solid surface.
Contaminant: Any foreign or unwanted substance that can have a negative effect on system operation, life or reliability.
Continuous Spectrum: A plot of the relative absorbance or intensity of emitted light vs. wavelength or frequency that shows a smooth variation, rather than a series of sharp peaks or bands.
CoO: Chemical formula for Cobalt II Oxide.
COOH: Carboxylic acid group.
Coordination Number: The number of atomic or ionic nearest neighbours.
Copernicium: Cp
Scientists from the Centre for Heavy Ion Research in Germany, led by Professor Sigurd Hofmann, discovered copernicium in fusion experiments in 1996.
Copolymer: A polymer that consists of two or more dissimilar mer units in combination along its molecular chains.
Copper: Noted for being ductile and having good electrical and thermal conductivity. It forms the basis of a number of alloys.
Copper I Bromide: CuBr
Yellowish green or white crystalline solid.
Copper I Chloride: CuCl
White crystalline solid. Turns green in moist air.
Copper I Iodide: CuI
White crystalline solid.
Copper I Oxide: Cu₂O
A red powder.
Copper I Sulphide: Cu₂S
Yellow, red, or brown crystalline solid.
Copper II Bromide: CuBr₂
Black crystalline solid. Reacts violently with potassium.
Copper II Carbonate: CuCO₃
Green or blue powder forming most of the patina one sees on weathered brass, bronze, and copper. Used as a pigment.
Copper II Hydroxide: Cu(OH)₂
Used as a fungicide.
Copper II Oxide: CuO
A black-brown crystalline solid.
Copper II Sulphide: CuS
Blue-black or black crystalline solid.
Copper Plating: The process in which a layer of copper is deposited on the item to be plated by using an electric current.
Copper Sulphate: CuSO₄
A water soluble salt used in copper plating.
Copperas: The mineral form of Iron II Sulphate.
Core Electron: Electrons occupying completely filled shells under the valence shell.
Cork: Outer waterproof layer covering most trees and shrubs. The cork material used in flooring and for it′s properties is from the tree Quercus Suber.
Corrosive: Having the power to dissolve. Can burn and destroy living tissue.
Corrosive Sublimate: Another name for Mercury II Chloride.
Coulombic Efficiency: For a rechargeable battery the fraction of the electrical charge stored during charging that is recoverable during discharge.
Coulombic Force: A force between charged particles, such as ions.
Coupled Reactions: Two chemical reactions that have a common intermediate and thus a means of energy transfer from one to the other.
Covalent Bond: Describes the mutual electrostatic attraction of two or more adjacent nuclei for a shared pair of electrons which occupy the same molecular energy level.
Covalent Compound: A compound in which the atoms that are bonded share electrons rather than transfer electrons from one to the other.
Covalent Radius: The radius of atoms obtained from covalent bond lengths.
Cr: Chromium is a bright, blue/white metal with excellent corrosion resistance.
Cr₂O₃: Chemical formula for Chromium Oxide.
Cracking: The thermal decomposition of the molecules of high molecular mass organic compounds to produce molecules of compounds of lower molecular mass.
C Rate: Battery discharge rate.
Critical Molar Volume: The molar volume at the critical point.
Critical Pressure: The pressure at the critical point.
Critical Temperature: The temperature at the critical point.
CrO₂: Chemical formula for Chromium Dioxide.
Crosslinked Polymer: A polymer in which adjacent linear molecular chains are joined at various positions by covalent bonds.
Crown Glass: A silicate glass containing oxides of sodium and potassium, used in compound lenses and spectacles; harder than flint glass, with low index and low dispersion.
Crown Gold: 2 carats of alloy (usually copper sometimes silver) and 22 carats of gold so called from the gold crown of 1526 which used this alloy.
Crude Oil: Unrefined oil as it comes directly from the well.
Cryogenic Gas: A gas that has been liquified by lowering the temperature, usually to a temperature under about -100�C.
Crystal: A material in which the atoms are arranged in a definite geometric pattern.
Crystal Field Splitting Energy: Ligands complexed to a metal ion will raise the energy of some of its d orbitals and lower the energy of others, the difference in energy is called the crystal field splitting energy.
Crystal Field Theory: The colour, spectra, and magnetic properties of metal-ligand complexes can be explained by modelling the effect of ligands on metal′s d orbital energies.
Crystal Orientation: Arrangements in space of the axes of a crystal lattice with respect to a coordinate system.
Crystal Structure: For crystalline materials, the manner in which atoms or ions are arrayed in space. It is defined in terms of the unit cell geometry and the atom positions within the cell.
Crystal System: A scheme by which crystal structures are classified according to unit cell geometry.
Crystalline: The state of a solid material characterized by a periodic and repeating three-dimensional arrays of atoms, ions, or molecules.
Crystallite: A region within a crystalline polymer in which all the molecular chains are ordered and aligned.
Crystallization: Act or process of forming crystals or bodies by elements or compounds solidifying.
Crystals of Silver: Old name for Silver Nitrate.
Cs: A soft metal which is often liquid at room temperature due to its relatively low melting point (28.5�C).
CS₂: Chemical formula for carbon disulphide.
Cs₂O: Chemical formula for Caesium Oxide.
Cs₂O₂: Chemical formula for Caesium Peroxide.
Cs₂S: Chemical formula for Caesium Sulphide.
CsBr: Chemical formula for Caesium Bromide.
CsCl: Chemical formula for Caesium Chloride.
CsF: Chemical formula for Caesium Fluoride.
CsH: Chemical formula for Caesium Hydride.
CsI: Chemical formula for Caesium Iodide.
CsO₂: Chemical formula for Caesium Superoxide.
Cu: Copper is a reddish coloured metal which is malleable and ductile. It has excellent thermal and electrical conductivities and good corrosion resistance.
Cu₂O: Chemical formula for Copper I Oxide.
Cu₂S: Chemical formula for Copper I Sulphide.
Cubic Nitre: Name for the crystallised form of Sodium Nitrate.
CuBr: Chemical formula for Copper I Bromide.
CuBr₂: Chemical formula for Copper II Bromide.
CuCl: Chemical formula for Copper I Chloride.
CuCO₃: Chemical formula for Copper II Carbonate.
CuI: Chemical formula for Copper I Iodide.
Cunife: An alloy of copper, nickel, iron, and in some cases cobalt.
CuO: Chemical formula for Copper II Oxide.
Cupric Bromide: Old name for Copper II Bromide.
Cupronickel: An alloy of copper and nickel that is resistant to corrosion.
Cuprum: The old name for Copper and from where the chemical symbol Cu was derived.
Cure: To irreversibly polymerize a thermosetting plastic by subjecting it to a time-temperature profile.
Curium: Man-made radioactive element.
CuS: Chemical formula for Copper II Sulphide.
CuSO₄: Chemical formula for Copper Sulphate.
Cyanide Process: A method for separating a metal from an ore.
Cyanocobolamin: Commonly known as vitamin B12.
Cyanoethene: Alternative name for Acrylonitrile.
Cyanogen: Colourless very poisonous gas that smells of bitter almonds.
Cycloalkanes: Saturated compounds containing only carbon and hydrogen atoms in which the carbon backbone forms a ring structure.
Cyclon: Alternative name for Hydrogen Cyanide.
Cysteine: C₃H₇NO₂S
A naturally occurring amino acid with an SH group on its side chain.
Cystine: C₆H₁₂N₂O₄S₂
A naturally occurring amino acid with a disulfide bridge group on its side chain, formed by condensation of two cysteine residues.
D₂O: Chemical formula for Heavy Water.
dalton: The atomic mass unit is sometimes called the dalton, after John Dalton.
Dalton, John: He developed atomic theory that accounts for the law of conservation of mass, law of definite proportions and law of multiple proportions.
Dalton′s Law of Partial Pressures: The total pressure of a mixture of gases, which do not interact chemically, is equal to the sum of the partial pressures.
Damps: Any dangerous vapours in caves, mines etc.
Darcets Alloy: A low melting point alloy.
Debye: Unit of dipole moment.
Decane: C₁₀H₂₂
Decane is one of the components of petrol. Like other alkanes, it is nonpolar and therefore will not dissolve in polar liquids such as water.
Decantation: To a separate the supernatant liquid from a solid precipitate by pouring the liquid off, being careful that all of the solid remains in the vessel.
Decoction: Continuous application of boiling heat to a reaction mixture.
Decomposition Reaction: A reaction in which a compound is broken down into simpler compounds or elements.
Decompounded: Doubly compounded, or composed of three or more substances.
Decrepitation: Rapid physical decomposition of some crystals when heated. Characterized by a crackling noise.
Deflagration: To cause a substance to burn rapidly, with flame.
Degas: Removing air from a liquid, usually by ultrasonic or vacuum methods.
Degenerate Orbital: A set of orbitals are said to be degenerate if they all have the same energy.
Degree of Polymerization: The average number of mer units per polymer chain molecule.
Dehydrator: A separator that removes water from the system fluid.
Deliquescence: Deliquescent compounds absorb so much moisture from the air that they dissolve.
Deliquium: Change of salt from a solid to a fluid state by contact with air only.
Demeon: Alternative name for Dimethyl Ether.
Denatured Alcohol: Poison is added to industrial ethanol so that the tax is not charged for industrial usage.
Density Functional Theory: A model that describes the electronic structure of an atom or molecule by approximating the total energy as a function of electron density.
Dephlegmation: To remove water from a solution, usually one of an acid or alcohol.
Dephlogisticated Air: An old name for oxygen.
Depuration: To free from impurities, purify.
Desalination: Removal of dissolved salts from seawater.
Desiccant: Any absorbent or adsorbent, liquid or solid, that will remove water or water vapor from a material.
Desiccator: A sealed container in which a drying agent is used to dry material that contains water.
Desolvation: In aqueous solution, the release of bound water surrounding a solute such as an enzyme.
Desorption: The opposite process of adsorption.
Desquamation: The process of removing scaly crusts which form on a surface.
Destructive Hydrogenation: The hydrocarbon chains are ruptured and hydrogen is added where the breaks have occurred.
Detonation: Any rapid chemical reaction accompanied by noise and often heat and light, e.g., explosions.
Deuterium: An isotope of hydrogen that contains one neutron and one proton in its nucleus.
Devitrification: The process in which a glass (noncrystalline or vitreous solid) transforms to a crystalline solid.
Dialuminium Hexachloride: Alternative name for Aluminium Chloride.
Dialuminium Trisulphide: Alternative name for Aluminium Sulphide.
Dialysis: The separation of components in a mixture by passing them across a semipermeable membrane.
Diamond: A crystalline form of carbon, made of a network of covalent, tetrahedrally bound carbon atoms.
Diastereomers: Optical isomers that are not mirror images of each other.
Diatomic Molecules: Molecules composed of two atoms eg CO.
Diazonium Salt: A compound with general form Ar-NN+X-, where Ar represents a substituted benzene ring and X- is a halide ion such as chloride.
Diazotization: A reaction that converts an -NH₂ group connected to a phenyl ring to a diazonium salt.
Dicaesium Oxide: Old name for Caesium Oxide.
Dicaesium Peroxide: Old name for Caesium Peroxide.
Dicaesium Sulphide: Old name for Caesium Sulphide.
Dichlorodiethyl Sulphide: (CH₂CH₂Cl)₂S
Oily gas used in warfare. Also known as mustard gas or yperite.
Dichlorogermylene: Alternative name for Germanium II Chloride.
Dichloromethane: CH₂Cl₂
Organic solvent often use to extract organic substances from samples.
Dicobalt Trioxide: Alternative name for Cobalt III Oxide.
Didymium: A mixture of praseodymium and neodymium believed to be an element until 1885.
Diethyl Ether: C₄H₁₀O
A clear, colourless, and highly flammable liquid with a low boiling point and a characteristic odor.
Differential Thermal Analysis: A technique that is often used to analyze materials that react or decompose at higher temperatures.
Diffusion: The mixing of two substances caused by random molecular motions.
Diffusion Flux: The quantity of mass diffusing through and perpendicular to a unit cross-sectional area of material per unit time.
Diffusion Rate: The number of randomly moving molecules that pass through a unit area per second.
Dihexyl: Another name for Dodecane.
Dihydrogen Monoxide: More commonly known as water.
Dihydrogen Selenide: Old name for Hydrogen I Selenide.
Dilatometer: A device for measuring volume changes.
Dilithium Oxide: Old name for Lithium I Oxide.
Dilithium Peroxide: Old name for Lithium I Peroxide.
Dilute: Having a relatively low concentration.
Dilution: Adding solvent to a solution to lower its concentration.
Dimanganese Heptoxide: Alternative name for Manganese VII Oxide.
Dimercury Dichloride: Another name for Mercury I Chloride.
Dimethyl Ether: CH₃OCH₃
Simplest ether, it is a colourless gas that is a useful precursor to other organic compounds and an aerosol propellant.
Dimethyl Ketone: Also known as acetone.
Dimethyl Oxide: Alternative name for Dimethyl Ether.
Dimethylbenzenes: Alternatively known as Xylol.
Dipole-Dipole Interaction: Electrostatic attraction between oppositely charged poles of two or more dipoles.
Dipotassium Oxide: Old name for Potassium Oxide.
Dipotassium Peroxide: Old name for Potassium Peroxide.
Diprotic Acid: An acid having two dissociable protons.
Discontinuity: A break in sequence or continuity of anything.
Disilver Sulphide: Old name for Silver Sulphide.
Disinfectant: A substance that kills or stops the growth of microbes.
Dislocation: A linear crystalline defect around which there is an atomic misalignment.
Disodium Oxide: Old name for Sodium Oxide.
Dispersant: An additive that reduces deposits on oil-wetted surfaces primarily through suspension of particles.
Displacement Reaction: A reaction in which a fragment of one reactant is replaced by another reactant or by a fragment of another reactant.
Disproportionation: A reaction involving a substance that produces two different forms of the substance, one more oxidized and the other more reduced than the original.
Dissociation: Breaking down of a compound into its components.
Dissolve: To mix a solid and a liquid to form a solution.
Dissolved Oxygen: The amount of oxygen dissolved in a solvent (usually water).
Distillate: The vapour collected and condensed from a distillation.
Distillation: A process used to separate a liquid from a solution.
Distillation Per Ascensum: Distillation with the collecting vessel above the heated vessel.
Distillation Per Decensum: Any distillation where the collecting vessel is below the heated vessel.
Distillation Per Obliquium: Distillation in a retort used for substances of relatively low vapor pressure and other properties that make distillation difficult.
Distillation with Addition: Adding some substance prior to distillation that will aid the process.
Disulfane: Old name for Hydrogen Persulphide.
Divalent: Binds to two other things: atoms, molecules, ions, or electrons.
Divalent Anion: An ion with a charge of -2.
Divalent Cation: An ion with a charge of +2.
Divinyl: Another name for 1,3-Butadiene.
Dodecane: C₁₂H₂₆
A thick, oily liquid of the paraffin series. It is used as a solvent, distillation chaser and is also the average component of diesel fuel.
Domoic Acid: C₁₅H₂₁NO₆
Domoic acid is a toxic amino acid produced by certain species of algae.
Doping: The intentional alloying of semiconductor materials with controlled concentrations of donor or acceptor impurities
Double Bond: When an atom is bonded to another atom by two sets of electron pairs.
Double Displacement: A reaction in which two reactants trade fragments.
Drinking Water: Water of sufficiently high quality that it can be consumed or used without risk of immediate or long term harm.
Drug: A biologically active compound or mixture used to cure, prevent, or detect disease, to control biological processes, or to alter mental state.
Dry Bulb Thermometer: A thermometer used to measure the ambient temperature.
Dry Cell: A electrolytic cell also known as a Leclanch� cell that uses a moist paste rather than a liquid as an electrolyte.
Dulcification: Any process in which a caustic substance is rendered less corrosive.
Duodecane: Another name for Dodecane.
Dutch Metal: A form of brass being an alloy of copper, 84% and zinc 16%.
Dy: Dysprosium is a silvery metal of the lanthanide group. It is relatively stable in air, reacts violently with water and dissolves in acids.
Dymel A: Alternative name for Dimethyl Ether.
Dynamic Equilibrium: Equilibrium which includes inertial forces.
Dynamite: A blasting explosive, based on nitroglycerine, but much safer to handle than nitroglycerine alone.
Dysprosium: A silvery metal of the lanthanide group. It is relatively stable in air, reacts violently with water and dissolves in acids.
E10 Ethanol: Ethanol mixture that contains 10% ethanol, 90% unleaded gasoline.
E85: Refers to a fuel blend of 85 percent ethanol and 15 percent gasoline.
E85 Ethanol: Refers to a fuel blend of 85 percent ethanol and 15 percent gasoline.
Ebulliometry: Determination of average molecular weight of a dissolved substance from the boiling point elevation of the solution.
Ebullition: The agitating, bubbling action of a liquid that is undergoing rapid, active boiling.
Effective Nuclear Charge: The nuclear charge experienced by an electron when other electrons are shielding the nucleus.
Effervescence: The rapid escape of gas from a liquid, usually due to chemical action.
Efflorescent: Efflorescent substances lose water of crystallization to the air.
Effusion: Movement of gas molecules through a small opening.
Einsteinium: An artificial radioactive element found in the debris of an H bomb.
Elastomer: A polymeric material that may experience large and reversible elastic deformations.
Electric Dipole: An object whose centres of positive and negative charge do not coincide.
Electric Dipole Moment: A measure of the degree of polarity of a polar molecule.
Electrochemistry: The study of the interchange of chemical and electrical energy.
Electrodeposition: The deposition of a substance on an electrode by passing electric current through an electrolyte.
Electrodes: Device that moves electrons into or out of a solution by conduction.
Electrokinetic Potential: Electric potential across all phase boundaries between solids and liquids, also known as the Zeta Potential.
Electromotive Series: The electrode potential of a material according to decreasing tendency to release electrons with hydrogen as zero.
Electron Affinity: The measure of an atom′s tendency to gain an electron.
Electron Configuration: A list showing how many electrons are in each orbital or subshell.
Electron Shell: A group of electrons which have a common energy level that forms part of the outer structure of an atom.
Electronegative: For an atom, having a tendency to accept valence electrons; also a term to describe non-metallic elements.
Electrophoresis: The migration of colloidal particles dispersed in a fluid, under the influence of an electric field.
Electropositive: For an atom, having a tendency to release valence electrons.
Electrorefining: A method for purifying a metal using electrolysis.
Electrostatic Interactions: Attractions between opposite charges or repulsions between like charges that grow stronger as the charges become closer to each other.
Electrovalence: The valence as determined by the electrons lost or gained by the elements reacting to form a compound.
Electrum: An alloy of 75% gold and 25% silver along with small quantities of other metals such as copper.
Element: A pure substance which cannot be broken down into simpler substances by chemical means.
Element Symbol: An international abbreviation for element names, usually consisting of the first one or two distinctive letters in element name.
Elementary Reaction: A reaction that occurs in a single step.
Emissions: The gases and airborne particles produced during combustion.
Emollient: A substance added to a formulation that gives it softening ability.
Empirical Law: A law strictly based on experiment, which may lack theoretical foundation.
Emulsion: A colloid formed from tiny liquid droplets suspended in another, immiscible liquid. E.g. Milk.
Enantiomers: Stereoisomers that are nonsuperimposable complete mirror images of each other.
Endergonic: Refers to a reaction for which the free energy of the system increases.
Endothermic: Reaction that absorbs heat from its surroundings as the reaction proceeds.
Endpoint: The experimental estimate of the equivalence point in a titration.
Energy Density: Characteristic parameter of a battery/electrical power source indicating the amount of electrical energy stored per unit weight or volume.
Enzyme: Protein or protein-based molecules that speed up chemical reactions occurring in living things.
Epsom Salts: Common name for Magnesium Sulphate.
Equivalence Point: Occurs when the moles of acid equal the moles of base in a solution.
Er: Erbium is a silvery grey metal that is a member of the lanthanide group of elements.
Erbium: A silvery grey metal that is a member of the lanthanide group of elements.
Errors: No measurement is exact, they all contain some degree of errors.
Erythrene: Another name for 1,3-Butadiene.
Es: Einsteinium artificial radioactive element found in the debris of an H bomb.
Essential Oil: Any oil that smells the same as the vegetable from which it was obtained and has a low boiling point.
Ester: Compound formed by the reaction between an alcohol and an acid, with the elimination of water.
Ethanal: Also known as acetaldehyde, it is a colourless fruity smelling liquid that with further oxidation forms acetic acid.
Ethanamide: Also known as Acetamide.
Ethane: C₂H₆
Second member of the alkane series, a colourless, odourless gas.
Ethanenitrile: Also known as Acetonitrile.
Ethanoic Acid: Alternative name for Acetic Acid.
Ethanol: C₂H₅OH
Prepared by the fermentation of sugar.
Ethanol E10: Ethanol mixture that contains 10% ethanol, 90% unleaded gasoline.
Ethanol E85: Refers to a fuel blend of 85 percent ethanol and 15 percent gasoline.
Ethanol E93: Ethanol mixture that contains 93% ethanol, 5% methanol and 2% kerosene, by volume.
Ethanol E95: Ethanol/gasoline mixture that contains 95% denatured ethanol and 5% gasoline, by volume.
Ethanoyl Chloride: Also known as Acetyl Chloride.
Ethene: Alternative name for Chloroform.
Ether: A class of organic compounds that contain an ether group which is an oxygen atom connected to two alkyl or aryl groups.
Etherification: Oxygenation of an olefin by methanol or ethanol.
Ethyl: The monovalent radical -C₂H₅
Ethyl Acetate: CH₃COOCH₂CH₃
A flammable liquid with a fruity odour, used in flavourings and as a solvent.
Ethyl Bromide: Alternative name for Bromoethane.
Ethyl Chloride: Alternative name for Chloroethane.
Ethyl Ether: Another name for Diethyl Ether.
Ethyl Oxide: Another name for Diethyl Ether.
Ethyl Tertiary Butyl Ether: A fuel oxygenate used as a gasoline additive to increase octane and reduce engine knock.
Ethylamine: CH₃CH₂NH₂
Widely used in chemical industry and organic synthesis, it has a strong ammonia-like odor.
Ethylene: Also known as Ethene this is a colourless inflammable gas with a sweet smell used as an anaesthetic and in the manufacture of polythene.
Ethylene Aldehyde: Alternative name for Acrolein.
Ethylene Vinyl Acetate: The copolymer of ethylene and vinyl acetate.
Ethylenecarboxylic Acid: Alternative name for Acrylic Acid.
Ethylenediaminetetraacetic Acid: C₁₀H₁₆N₂O₈
A polydentate ligand that tightly complexes certain metal ions.
Ethyne: Also known as Acetylene, used for welding as the flame temperature is roughly 3300�C when burnt with oxygen.
Eu: A europium is a ductile silvery metal which reacts rapidly with air and water.
Europium: A ductile silvery metal which reacts rapidly with air and water.
Eutectic Alloy: An alloy that changes directly from a solid to a liquid with no plastic or semiliquid state.
Eutectic Mixture: A mixture of two or more substances with melting point lower than that for any other mixture of the same substances.
Eutectic Point: The melting point of a eutectic mixture.
EVA: Common abbreviation of Ethylene Vinyl Acetate.
Excitotoxin: An excitotoxin is a toxic molecule that stimulates nerve cells so much that they are damaged or killed.
Exergonic: Refers to a reaction for which the free energy of the system decreases.
Exothermic: Reaction that gives off heat to the environment.
Experimental Yield: The measured amount of product produced in a chemical reaction.
Extensive Properties: Properties which are dependent on the amount of the substance.
Extrinsic Semiconductor: A semi-conducting material for hich the electrical behavior is determined by impurities.
F: Fluorine is a pale greenish yellow gas that is the first in the halogen group.
Face Centred Cubic: Roughly 20% of the elements crystallize with face centred cubic structures.
Facilitated Diffusion: Diffusion of a molecule across a biological membrane via a protein transporter down a concentration gradient.
Faints: Name given to the impure spirit which comes over first and last in distillation.
Famous Scientists & Engineers: Lists all the Famous Scientists & Engineers in the Encyclopaedia
Fatigue: An important mode of failure of engineering components subjected to dynamic stresses.
Fatty Acid: Carboxylic acids with long hydrocarbon side chains.
Fe: Iron is one of the most abundant metallic elements (41000 ppm) and probably one of the most important, being used on the largest scale of any metal.
Fe₂O₃: Chemical formula for Iron III Oxide.
FeCl₂: Chemical formula for Iron II Chloride.
FeCl₃: Chemical formula for Iron III Chloride.
FeO: Chemical formula for Iron II Oxide.
Fermentation: A class of biochemical reactions that break down complex organic molecules into simpler materials.
Fermium: A man-made element with an atomic number of 100.
Ferric Oxide: Old name for Iron III Oxide.
Ferroelectric: A dielectric material that may exhibit polarization in the absence of an electric field.
Ferroin: C₃₆H₂₄FeN₆⁺²
A blood-red complex of Fe2+ ion with 1,10-phenanthroline, used as a redox indicator. Ferroin changes from red to pale blue when oxidized.
Ferromagnetism: Permanent and large magnetizations found in some metals (e.g., Fe, Ni, and Co), which result from the parallel alignments of neighboring magnetic moments.
Ferrous Chloride: Old name for Iron II Chloride.
Ferrous Metal: A metal alloy in which iron is the major ingredient.
Ferrous Oxide: Old name for Iron II Oxide.
Ferrous Sulphide: Old name for Iron Sulphide.
Ferrum: Latin for iron, hence the symbol Fe.
FeS: Chemical formula for Iron Sulphide.
FeS₂: Chemical formula for Iron II Sulphide.
FeSO₄: Chemical formula for Iron II Sulphate.
Fibre: Any material that has been drawn into a cylinder with a length-to-diameter ratio greater than about ten.
Fields Metal: A low melting point alloy. 51% Indium, 32.5% Bismuth, and 16.5% Tin.
A non-toxic replacement for Wood's Metal.
Filler: An inert foreign substance added to a matrix to improve or modify its properties.
Fire Air: An old name given to pure oxygen.
Fire Damp: The gases found naturally in coal are a mixture of methane and other hydrocarbons. Given the name as they are highly combustible when mixed with air.
First Order Reaction: The sum of concentration exponents in the rate law for a first order reaction is one. Many radioactive decays are first order reactions.
Fischer-Tropsch: A method discovered in 1923 by the German coal researchers Franz Fischer and Hans Tropsch, for the synthesis of hydrocarbons and other aliphatic compounds.
Flame Test: A test to identify some metals, e.g. with sodium the flame turns orange.
Flammable: Substance that can easily be set on fire and that will burn readily or quickly.
Flash Point: The temperature when vapour pressure of a substance becomes high enough to allow the air/vapour layer over the substance to be ignited.
Flint Glass: An optical glass with higher dispersion and higher refractive index than crown glass; a heavy, brilliant glass, softer than crown glass.
Florentine Bronze: A modern term for an alloy usually formed as a mixture of aluminium or tin (<10%) and copper (>90%).
Flowers of Antimony: Alternative name for Antimony Trioxide.
Fluorescence: The property of a material whereby it emits visible light when it is illuminated by ultraviolet light.
Fluorine: A pale greenish yellow gas that is the first in the halogen group.
Fluorotrichloromethane: Alternative name for Trichlorofluoromethane.
Fm: Fermium is a man-made element with an atomic number of 100.
Foam: A colloid in which bubbles of gas are suspended in a solid or liquid.
Fools Gold: Name given to Iron II Sulphide due to its colour and texture.
Formaldehyde: H₂CO
Used widely by industry to manufacture building materials and numerous household products. It is also a by-product of the incomplete combustion of carbo containing materials.
Formation Reaction: A reaction that forms one mole of a compound from its elements in their most stable forms.
Formic Acid: Another name for Methanoic Acid.
Formic Anammonide: Alternative name for Hydrogen Cyanide.
Formonitrile: Alternative name for Hydrogen Cyanide.
Formula Unit: One formula weight of a compound.
Formula Weight: The formula weight is the sum of the atomic weights of the atoms in an empirical formula.
Formyl Trichloride: Alternative name for Chloroform.
Formylic Acid: Another name for Methanoic Acid.
Fossil Fuel: A fuel such as coal, oil or natural gas that was formed through the decomposition of ancient plant and animal life.
Fr: Francium is the heaviest alkali metal with no stable isotopes.
Fractional Distillation: A technique for separation of liquid mixtures by distillation that uses a tower attached to a flask containing the mixture to perform multiple distillations.
Francium: The heaviest alkali metal with no stable isotopes.
Free Radical: A molecule with an odd number of electrons.
Freeze: To change from a liquid to a solid by cooling.
Frenkel Defect: In an ionic solid, a cation-vacancy and cation-interstitial pair.
Freon-10: Alternative name for Carbon Tetrachloride.
Freon-11: Alternative name for Trichlorofluoromethane.
Freon-14: Alternative name for Tetrafluoromethane.
Fuel: Any substance burned for heat or power.
Fuel Additives: Chemicals added to fuel in very small quantities to improve and maintain fuel quality and/or to lower emissions.
Fuel Cell: A device that converts the chemical energy obtained from a redox reaction directly into electrical energy.
Fugacity: The expression of activity for a component in a mixture of gases.
Fullerene: A form of carbon consisting of 60 carbon atoms bound together to make a roughly spherical buckyball.
Fulmination: Any very rapid reaction which produces heat, light, and noise - explosions.
Functional Group: A substructure that imparts characteristic chemical behaviours to a molecule, for example, a carboxylic acid group.
Furanose Ring: A five-membered cyclic hemiacetal or hemiketal of a carbohydrate.
Fused Quartz: The glassy isotropic form of quartz.
Fused Silica: SiO₂
The glassy isotropic form of quartz.
Ga: Gallium is one of four metals which can be liquid at room temperature
Ga₂I₆: Chemical formula for Gallium III Iodide.
Ga₂O₃: Chemical formula for Gallium III Oxide.
Ga₂Se₃: Chemical formula for Gallium III Selenide.
Ga₂Te₃: Chemical formula for Gallium III Telluride.
GAA: Abbreviation of Glacial Acetic Acid.
GaBr₃: Chemical formula for Gallium III Bromide.
GaCl₃: Chemical formula for Gallium III Chloride.
Gadolinium: A silvery white metal which is ductile and malleable. It is stable in a dry atmosphere but forms an oxide coating when exposed to moist air.
GaF3: Chemical formula for Gallium III Fluoride.
Galena: A Lead Sulphide and the most common ore of lead.
Gallium: One of four metals which can be liquid at room temperature.
Gallium II Selenide: GaSe
Has been used as a non-linear optical material.
Gallium II Telluride: GaTe
Made by reacting the elements or by metal organic vapour deposition.
Gallium III Bromide: GaBr₃
White powder that is soluble in water.
Gallium III Chloride: GaCl₃
The main precursor to most derivatives of gallium and a reagent in organic synthesis.
Gallium III Fluoride: GaF₃
White solid.
Gallium III Hydroxide: Ga(OH)₃
The normal form of Gallium in the Earth′s crust.
Gallium III Iodide: Ga₂I₆
The most common iodide of gallium.
Gallium III Oxide: Ga₂O₃
White crystalline powder prepared by thermal decomposition of gallium salts.
Gallium III Selenide: Ga₂Se₃
P-type semiconductor. Reddish-black crystals with a slight garlic odour.
Gallium III Telluride: Ga₂Te₃
Used as a semiconductor.
Gallium Monoselenide: Alternative name for Gallium II Selenide.
Gallium Nitride: GaN
A binary III/V direct bandgap semiconductor commonly used in bright light-emitting diodes.
Gallium Phosphide: GaP
Used in the manufacture of low-cost red, orange, and green light-emitting diodes.
Gallium Sesquioxide: Alternative name for Gallium III Oxide.
Gallium Tribromide: Alternative name for Gallium III Bromide.
Gallium Trichloride: Alternative name for Gallium III Chloride.
Gallium Trifluoride: Alternative name for Gallium III Fluoride.
Gallium Trihydroxide: Alternative name for Gallium III Hydroxide.
Gallium Triiodide: Alternative name for Gallium III Iodide.
Gallium Trioxide: Alternative name for Gallium III Oxide.
Gallium Triselenide: Alternative name for Gallium III Selenide.
Galvanic Cell: A cell in which chemical change is the source of electrical energy.
Galvanic Corrosion: Corrosion associated with the current of a galvanic cell consisting of two dissimilar conductors in an electrolyte or two similar conductors in dissimilar electrolytes.
Galvanic Couple: A pair of dissimilar conductors, commonly metals, in electrical contact.
Galvanic Current: The electric current that flows between metals or conductive nonmetals in a galvanic couple.
Gamma Iron: The face-centered cubic form of pure iron, stable from 910 to 1400�C.
GaN: Chemical formula for Gallium Nitride.
GaP: Chemical formula for Gallium Phosphide.
Gas: Matter with no definite shape or volume.
Gas Constant: Molar Gas Constant, R = 8.31441 JK^-1mol^-1
Gas to Liquid Technology: Gas-to-liquid conversion technologies that use chemical or physical means to convert natural gas to a liquid form suitable for road transport or direct use.
GaSe: Chemical formula for Gallium II Selenide.
Gasification: A process for converting materials such as coal, petroleum, or biomass, into carbon monoxide and hydrogen by reacting the raw material at high temperatures with a controlled amount of oxygen.
GaTe: Chemical formula for Gallium II Telluride.
Gay-Lussac, Joseph Louis: Developed the law of volumes concerning the combination of gases and discovered boron.
Gay-Lussac′s Law: When gases react, they do so in a definite proportion by volume, if the volumes are measured at the same pressure and temperature.
Gd: Gadolinium is a silvery white metal which is ductile and malleable. It is stable in a dry atmosphere but forms an oxide coating when exposed to moist air.
Ge: Germanium is a silvery white brittle metalloid member of the carbon group of elements. Its physical properties being similar to those of silicon.
GeCl₂: Chemical formula for Germanium II Chloride.
GeCl₄: Chemical formula for Germanium IV Chloride.
GeH₄: Chemical formula for Germane.
Gel: A sol in which the solid particles fuse or entangle to produce a rigid or semirigid mixture.
Gel Cell: A technique for sealed lead-acid batteries. The electrolyte solution is in a gel form, usually silica gel, instead of plain liquid.
Gel Filtration: A chromatographic procedure for the separation of a mixture of molecules on the basis of size.
GeO: Chemical formula for Germanium Monoxide.
GeO₂: Chemical formula for Germanium IV Oxide.
Geochemistry: The study of materials and chemical reactions in rocks, minerals, magma, seawater, and soil.
Geometric Isomer: Molecules that have the same molecular formula and bond connections, but distinctly different shapes.
German Silver: This describes a number of alloys that contain copper (25 to 50%), zinc (10 to 35%) and nickel (5 to 35%) within the limits given.
Germane: GeH₄
Used in the semiconductor industry for the epitaxial growth of germanium.
Germania: Another name for Germanium IV Oxide.
Germanium: A silvery white brittle metalloid member of the carbon group of elements. Its physical properties being similar to those of silicon.
Germanium Chloride: Alternative name for Germanium IV Chloride.
Germanium Dichloride: Alternative name for Germanium II Chloride.
Germanium Dioxide: Another name for Germanium IV Oxide.
Germanium Disulphide: Alternative name for Germanium IV Sulphide.
Germanium II Chloride: GeCl₂
White-pale yellow solid which on warming gives brown germanium monoxide.
Germanium II Selenide: GeSe
Black crystalline powder having orthorhombic crystal symmetry.
Germanium IV Chloride: GeCl₄
Colourless liquid used as an intermediate in the production of purified germanium metal.
Germanium IV Oxide: GeO₂
Refractive index and optical dispersion properties make it useful as an optical material for wide-angle lenses and in optical microscope objective lenses.
Germanium IV Sulphide: GeS₂
White crystalline solid.
Germanium Monoxide: GeO
Prepared as a yellow sublimate at 1000�C by reacting GeO₂ with Ge metal.
Germanium Selenide: Alternative name for Germanium II Selenide.
Germanium Telluride: GeTe
Shows semimetallic conduction and ferroelectric behaviour.
Germanium Tetrachloride: Alternative name for Germanium IV Chloride.
Germanium Tetrahydride: Alternative name for Germane.
Germanomethane: Alternative name for Germane.
GeS₂: Chemical formula for Germanium IV Sulphide.
GeSe: Chemical formula for Germanium II Selenide.
GeTe: Chemical formula for Germanium Telluride.
Gibbs Free Energy: A function of the system related to Suniv. It is used to determine the spontaneity of a reaction.
Gibbsite: White crystalline mineral consisting of aluminum hydroxide; a constituent of bauxite and a source of alumina.
Gilding Metal: A form of brass, comprising 95% copper and 5% zinc. Used to make items that were to be gilded.
Glass: Transparent or translucent substance that is physically neither a solid or liquid. It is made by fusing certain types of sand (silica).
Glass Ceramic: A fine-grained crystalline material that was formed as a glass and subsequently devitrified (crystallized).
Glass Transition Temperature: The temperature at which, upon cooling, a noncrystalline ceramic or polymer transforms from a supercooled liquid into a rigid glass.
Glucose: A sugar. It is made by plants during photosynthesis.
Glue: Cement or adhesive that is used to fix two or more parts together.
Glycerol: Thick sweet liquid used in the manufacture of explosives.
Glycine: NH₂CH₂COOH
A naturally occurring aliphatic amino acid, found in large quantities in gelatin.
Gold: A soft metal with a characteristic yellow colour. It is the most malleable and ductile of any element. It is unaffected by air, water, alkalis and acids.
GOx: Abbreviation of Gaseous Oxygen.
Graphene: An allotrope of carbon, whose structure is one-atom-thick planar sheets of sp²-bonded carbon atoms that are densely packed in a honeycomb crystal lattice.
Graphite: An amorphous form of carbon, made of carbon atoms bound hexagonally in sheets.
Green Vitriol: Hydrated Iron II Sulphate.
Greenockite: Mineral, main source of cadmium sulphide.
Group: A vertical column in the periodic table.
Guaranine: An alkaloid extracted from guarana, the same as Caffeine.
Gunmetal: This is a copper-tin alloy, similar to bronze, used where resistance to corrosion and/or wear required. Composition: 88% copper, 8% tin, 4% zinc.
Gunpowder: Any of several low-explosive mixtures.
Gy: An abbreviation of gray, the amount of energy actually absorbed in some material, and is used for any type of radiation and any material.
Gypsum: The old name for Calcium Sulphate.
H: Hydrogen is the least dense element. It has metallic and non-metallic properties.
H₂C₂O₄: Chemical formula for Oxalic Acid.
H₂CO: Chemical formula for Formaldehyde.
H₂CO₃: Chemical formula for Carbonic Acid.
H₂O: Chemical formula for water
H₂O₂: Hydrogen peroxide.
H₂S: Hydrogen sulphide.
H₂Se: Chemical formula for Hydrogen I Selenide.
H₂SO₃: Chemical formula for Sulphurous Acid.
H₂SO₄: Chemical formula for Sulphuric Acid.
H₂Te: Chemical formula for Hydrogen I Telluride.
H₃PO₄: Chemical formula for Phosphoric Acid.
ha: An abbreviation of hectare, a derived SI unit of area that is mainly used in agriculture to describe the area of fields.
Haber Process: An industrial process in which ammonia is manufactured by direct combination of its elements.
Hafnium: A silvery coloured, ductile metal which is found in all minerals containing zirconium.
Halide: A compound composed of two elements, one of which is a halogen (flourine, chlorine, bromine, iodine and astatine).
Halogen: Group of elements with similar bonding properties, consisting of flourine, chlorine, bromine, iodine and astatine.
Halon: Organic chemical compounds containing one or two carbon atoms, together with bromine and other halogens.
Hartree: The atomic unit of energy, named after the British physicist Douglas Hartree.
Hartshorn: Another name for Ammonium Bicarbonate.
Hazard: The potential that the use of a product will result in an adverse effect on a person or the environment.
HC: Abbreviation of Hydrocarbon.
HCL: Hydrochloric acid.
HCL: Hydrogen chloride.
HCN: Chemical formula for Hydrogen Cyanide.
HCP: Abbreviation of Hexagonal Close Packed, a crystal structure found for some metals.
He: Helium is an inert gaseous element.
Heat Value: The heat developed by the combustion of one pound of fuel, Btu per Pound.
Heavy Metals: Metallic elements with high atomic weights can damage living things at low concentrations and tend to accumulate in the food chain.
Heavy Water: D₂O
Water that contains ²H, rather than ¹H. Heavy water is about 11% denser than ordinary water.
Helium: An inert gaseous element.
Helmholtz Free Energy: Energy released or absorbed in a reaction occurring reversibly at constant volume and temperature.
Hendecane: Another name for Undecane.
Hepatic Air: Old name for hydrogen sulphide.
Heptane: C₇H₁₆
An alkane hydrocarbon. A constituent of petroleum.
Hermetic: Sealing of an object so it is airtight.
Hess′s Law: In going from a particular set of reactants to a particular set of products, the enthalpy change is the same whether the reaction takes place in one step or a series of steps; in other words, enthalpy is a state function.
Heterocyclic Compounds: In chemistry, heterocyclic compounds are cyclic compounds in which the ring system of the molecule contains other elements than carbon.
Heterogeneous Catalysis: A form of catalysis in which the catalyst is in a different physical state than the reactants.
Heterogeneous Mixture: A sample of matter consisting of more than one pure substance and more than one phase.
Hexacarbonylmolybdenum: Alternative name for Molybdenum Hexacarbonyl.
Hexagonal Close Packed: A crystal structure found for some metals.
Hexane: C₆H₁₄
Hexane isomers are largely unreactive, and are frequently used as an inert solvent in organic reactions because they are very non-polar.
Hf: Hafnium is a silvery coloured, ductile metal which is found in all minerals containing zirconium.
HF: Chemical formula for Hydrofluoric Acid.
Hg: The most common liquid metal at room temperature.
Hg₂Cl₂: Chemical formula for Mercury I Chloride.
HgCl₂: Chemical formula for Mercury II Chloride.
HgO: Chemical formula for Mercury II Oxide.
HgS: Mercuric Sulphide, the ore of mercury. Occuring as red crystals.
HI: Chemical formula for Hydrogen Iodide.
High Performance Liquid Chromatography: An efficient form of column chromatography that pumps a liquid solution of the sample at very high pressure through a column packed with a stationary phase made of very tiny particles.
High Spin Complex: A metal-ligand complex with the same number of unpaired electrons as the uncomplexed metal ion.
HNO₃: Chemical formula for Nitric Acid.
Ho: Holmium is a member of the lanthanide group with properties closely resembling those of erbium and dysprosium.
Holmium: A member of the lanthanide group with properties closely resembling those of erbium and dysprosium.
Homogeneous: Having uniform properties or composition.
Homogeneous Catalysis: A form of catalysis in which the catalyst is in the same physical state as the reactants.
Homogeneous Mixture: A sample of matter consisting of more than one pure substance with properties that do not vary within the sample.
Homologous Series: A series of organic compounds with a similar general formula, possessing similar chemical properties due to the presence of the same functional group, and shows a gradation in physical properties as a result of increase in molecular size and mass.
Homopolymer: A polymer having a chain structure in which all mer units are of the same type.
HRb: Chemical formula for Rubidium Hydride.
Humectant: A substance that absorbs or retains moisture, added to a product to keep it from drying out.
Hunds Rule: When electrons are put into orbitals having the same energy, degenerate orbitals, one electron is put into each orbital before putting a second electron into an orbital.
Hybrid Orbitals: The combination of a set of atomic orbitals to produce a new set of hybrid orbitals.
Hydrargyrum: The old name for Mercury and from where the chemical symbol Hg was derived.
Hydrate: A compound that has discrete water molecules combined with it.
Hydrated Beryllia: Alternative name for Beryllium Hydroxide.
Hydration: The combination of water and another substance to produce a single product.
Hydration Number: The number of water molecules associated with an ion in the process of solvation in aqueous solutions.
Hydraulic Set Cement: A cement that sets through reaction with water.
Hydrazine: NH₂NH₂
A colourless, fuming, corrosive liquid that is a powerful reducing agent.
Hydride: A compound containing a negatively charged hydrogen.
Hydrocarbon: A chemical containing only hydrogen and carbon.
Hydrochloric Acid: HCl
A solution of hydrogen chloride in water. Concentrated acid is a colourless, fuming, corrosive liquid.
Hydrochloride: Alternative name for Hydrogen Chloride.
Hydrocyanic Acid: A solution of Hydrogen Cyanide in water.
Hydrofluoric Acid: HF
Aqueous solution of hydrogen fluoride. Dissolves most metals and etches glass.
Hydrogen: The least dense element. It has metallic and non-metallic properties.
Hydrogen Arsenide: AsH₃
Intensely poisonous colourless gas. Also known as Arsine.
Hydrogen Bonding: Strong type of intermolecular dipole-dipole attraction. Occurs between hydrogen and fluorine, oxygen or nitrogen.
Hydrogen Carboxylic Acid: Another name for Methanoic Acid.
Hydrogen Chloride: Dissolves in water to produce hydrochloric acid.
Hydrogen Cyanide: HCN
Colorless, very poisonous and highly volatile liquid.
Hydrogen I Nitride: Modern name for Ammonia.
Hydrogen I Selenide: H₂Se
Colourless gas.
Hydrogen I Telluride: H₂Te
Colourless gas.
Hydrogen Iodide: HI
Colourless gas.
Hydrogen Peroxide: H₂O₂
A colourless, viscous, unstable liquid compound of hydrogen and water with oxidising and reducing properties. Used for bleaching wool, silk, linens, furs and hair products since the 19th century. During the Second World War hydrogen peroxide was used as a propellant in V1 rockets and was subsequently also used as a propellant for submarines. Hydrogen peroxide is also used as a preservative and disinfectant and is used by archaeologists to dissolve clay from finds.
Hydrogen Persulphide: H₂S₂
Colourless liquid.
Hydrogen Sulphide: Poisonous and smells of rotten eggs.
Hydrogenation: A chemical reaction in which hydrogen is added to a compound.
Hydroiodic Acid: Alternative name for Hydrogen Iodide.
Hydrolysis: When water reacts with another substance and as a result the oxygen in water makes a bond with the substance.
Hydrophilic: A polar molecule or group that can form strong hydrogen bonds with water.
Hydrophobic: A nonpolar molecule or group that has little affinity for water.
Hydroquinone: A reducing agent used in photographic developers.
Hydrous: A substance that contains water. The opposite of anhydrous.
Hydroxide: The OH^- ion or compounds containing the OH^- ion.
Hydroxy Group: An -OH group attached to an organic molecule.
Hydroxybutanedioic Acid: C₄H₆O₅
An organic dicarboxylic acid extracted from apples and various other fruits.
Hygroscopic: Able to absorb moisture from air.
Hypergolic Mixture: An oxidizing agent and a fuel that react or ignite instantly and spontaneously on contact.
Hypertonic: A solution which has higher osmotic pressure than some other solution.
I: Iodine is in the halogen group of elements.
Ice: Formed when water is cooled below its freezing point.
Ideal Solution: All molecules interact in exactly the same way; the solvent-solvent, solvent-solute, and solute-solute intermolecular forces are all equivalent.
Immiscible: Incapable of being mixed.
In: Indium is a soft, malleable and ductile metal which is generally unaffected by air or water but is soluble in acids.
In₂O₃: Chemical formula for Indium III Oxide.
In₂S₃: Chemical formula for Indium III Sulphide.
In₂Se₃: Chemical formula for Indium III Selenide.
In₂Te₃: Chemical formula for Indium III Telluride.
InAs: Chemical formula for Indium Arsenide.
InBr: Chemical formula for Indium I Bromide.
InBr₃: Chemical formula for Indium III Bromide.
InCl₃: Chemical formula for Indium III Chloride.
Inclusion: Foreign particle present as an undesirable impurity in a material.
Incomplete Combustion: A combustion reaction or process that does not convert all of the fuel′s carbon and hydrogen into carbon dioxide and water, respectively.
Incomplete Octet: An atom with less than eight electrons in its valence shell.
Inconel: A nickel based alloy with good corrosion resistance.
Indicator: A substance that undergoes a sharp, easily observable change when conditions in its solutions change.
Indicator Diagram: A plot of pressure vs. volume.
Indirect Titration: Determining the concentration of an analyte by reacting it with a known number of moles of excess reagent.
Indium: A soft, malleable and ductile metal which is generally unaffected by air or water but is soluble in acids.
Indium Antimonide: InSb
A narrow gap semiconductor material from the III-V group used in infrared detectors, including thermal imaging cameras, FLIR systems, infrared homing missile guidance systems, and in infrared astronomy.
Indium Arsenide: InAs
A semiconductor material that has the appearance of grey cubic crystals and is used for construction of infrared detectors.
Indium Gallium Aluminium Nitride: InGaAlN
Semiconductor that is the base for blue LEDs.
Indium Gallium Arsenide: InGaAs
Semiconductor used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide.
Indium Gallium Nitride: Semiconductor material made from a mix of Gallium Nitride and Indium Nitride.
Indium Gallium Phosphide: InGaP
Semiconductor composed of indium, gallium and phosphorus used in high-power and high-frequency electronics.
Indium I Bromide: InBr
A red crystalline compound made from heating the Indium metal with InBr₃.
Indium III Bromide: InBr₃
Hygroscopic yellow-white monoclinic crystals.
Indium III Chloride: InCl₃
Colourless salt finds some use in organic synthesis as a Lewis acid and is also the most available soluble derivative of indium.
Indium III Fluoride: InF₃
Used in the synthesis on non-oxide glasses.
Indium III Oxide: In₂O₃
Used as an n-type semiconductor and as a resistive element in integrated circuits.
Indium III Selenide: In₂Se₃
Potential for use in photovoltaic devices and it has been the subject of extensive research.
Indium III Sulphate: In₂(SO₄)₃
White-grey odourless powder, hygroscopic.
Indium III Sulphide: In₂S₃
The first indium compound ever described.
Indium III Telluride: In₂Te₃
Forms blue cubic crystals.
Indium Monoarsenide: Alternative name for Indium Arsenide.
Indium Nitride: InN
Small bandgap semiconductor material which has potential application in solar cells and high speed electronics.
Indium Phosphide: InP
A binary semiconductor used in high-power and high-frequency electronics.
Indium Sesquiselenide: Alternative name for Indium III Selenide.
Indium Tin Oxide: ITO
Main feature is the combination of electrical conductivity and optical transparency.
Inductive Effect: An inductive effect is the polarization of a chemical bond caused by the polarization of an adjacent bond.
Inert Gas: A gas which does not normally combine chemically with other elements.
Inert Pair: Valence electrons in an s orbital penetrate to the nucleus better than electrons in p orbitals, and as a result they′re more tightly bound to the nucleus and less able to participate in bond formation.
Inflammable Air: An old name for Hydrogen.
Infra-Red Spectroscopy: A technique for determining the structure of molecules by observing how infrared radiation is absorbed by a sample.
InGaAlN: Chemical formula for Indium Gallium Aluminium Nitride.
InGaAs: Chemical formula for Indium Gallium Arsenide.
InGaP: Chemical formula for Indium Gallium Phosphide.
Inhibitor: An additive used to retard undesirable chemical action in a product.
Initiator: A compound required to start a chain reaction.
InN: Chemical formula for Indium Nitride.
Inorganic Material: Substances not derived from living things.
InP: Chemical formula for Indium Phosphide.
InSb: Chemical formula for Indium Antimonide.
Insoluble: Refers to a substance that does not dissolve in a solvent to any significant degree.
Intensive Properties: Properties which are independent of the amount of the substance.
Interdiffusion: Diffusion of atoms of one metal into another metal.
Intermediate Solid Solution: A solid solution or phase having a composition range that does not extend to either of the pure components of the system.
Intermediate Species: Species formed in a reaction consisting of more than one step.
Intermetallic: A compound of two metals that has a distinct chemical formula. The bonds in intermetallic compounds are often partly ionic.
Intermolecular Forces: Forces between molecules.
Internal Energy: A property of a system that can be changed by a flow of work, heat or both.
Interstitial Site: Octahedral and tetrahedral open spaces within a close-packed arrangement of atoms or ions in which a cation can fit.
Interstitial Solid Solution: A solid solution wherein relatively small solute atoms occupy interstitial positions between the solvent or host atoms.
Intramolecular Forces: Forces within molecules. Forces caused by the attraction and repulsion of charged particles.
Intumescent: A substance which swells as a result of heat exposure, thus increasing in volume, and decreasing in density.
Invar: An alloy of iron and nickel.
Iodine: In the halogen group of elements.
Iodine Number: The number of grams of iodine required to saturate 100 grams of fat.
Ion: An atom, or group of atoms, which has either gained or lost electrons.
Ion Dipole Forces: Intermolecular force that exist between charged particles and partially charged molecules.
Ion Exchange: An exchange of ions between two electrolytes or between an electrolyte solution and a complex.
Ion Exchange Resin: A method of separating ions from a solution by reversibly binding them onto a resin that has charged sites on its surface.
Ionic Bond: This describes the electrostatic attraction of two oppositely charged ions in a crystalline lattice.
Ionic Compound: A compound made of distinguishable cations and anions, held together by electrostatic forces.
Ionic Dissociation: When ionic substances dissolve, their ions are surrounded by solvent molecules and separated from each other.
Ionic Radius: The radii of anions and cations in crystalline ionic compounds, as determined by consistently partitioning the centre-to-centre distance of ions in those compounds.
Ionic Strength: A measure of strength of a solution based on both the concentrations and valences of the ions present.
Ionization Energy: Energy required to remove an electron from a specific atom.
Ionizing Radiation: A particle or a photon with enough energy to knock off an electron from an atom.
Ir: Iridium is a rare, precious metallic element which is hard, brittle and has a low ductility.
IrF₄: Chemical formula for Iridium IV Fluoride.
IrF₅: Chemical formula for Iridium V Fluoride.
IrF₆: Chemical formula for Iridium VI Fluoride.
Iridium: A rare, precious metallic element which is hard, brittle and has a low ductility.
Iridium Hexafluoride: Alternative name for Iridium VI Fluoride.
Iridium IV Fluoride: IrF₄
Dark brown solid.
Iridium IV Oxide: IrO₂
The only well characterised oxide of iridium.
Iridium Pentafluoride: Alternative name for Iridium V Fluoride.
Iridium Tetrafluoride: Alternative name for Iridium IV Fluoride.
Iridium V Fluoride: IrF₅
A highly reactive yellow low melting solid.
Iridium VI Fluoride: IrF₆
A volatile and highly reactive yellow solid, with an octahedral molecular structure.
Iridosmine: Iridosmine (osmiridium) is a naturally occurring alloy of osmium and iridium.
IrO₂: Chemical formula for Iridium IV Oxide.
Iron: One of the most abundant metallic elements (41000 ppm) and probably one of the most important, being used on the largest scale of any metal.
Iron Hydroxide: FeO(OH)
Found as the minerals Siderogel and Feroxyhyte. It also has a variant known as Lepidocrocite.
Iron II Chloride: FeCl₂
Pale yellow to white crystalline solid.
Iron II Hydroxide: Fe(OH)₂
Green colour.
Iron II Oxide: FeO
Black colour powder. The powder in particular can cause explosions as it readily ignites.
Iron II Sulphate: FeSO₄
Also known as the mineral Melanterite or Copperas. Green Vitriol is hydrated Iron II Sulphate.
Iron II Sulphide: FeS₂
A brassy yellow colour. Also known as pyrite, iron pyrites and fools gold.
Iron III Chloride: FeCl₃
Brown black or green crystalline solid.
Iron III Oxide: Fe₂O₃
Known in its natural state as Haematite, but also purified for use as a coating in magnetic audio and computer media, where it is known as Ferric oxide.
Iron Pyrites: Old name for Iron II Sulphide.
Iron Sulphide: FeS
White crystalline solid.
Isoelectric: Refers to a group of atoms or ions having the same number of electrons.
Isoleucine: C₆H₁₃NO₂
A naturally occuring amino acid with a nonpolar side chain.
Isomer: Molecules with identical molecular formulas but different structural formulas.
Isomerism: The phenomenon whereby two or more polymer molecules or mer units have the same composition but different structural arrangements and properties.
Isomerization: A chemical change that involves a rearrangement of atoms and bonds within a molecule, without changing the molecular formula.
Isosteric: Having identical valence electron configurations.
Isotactic: A type of polymer chain configuration wherein all side groups are positioned on the same side of the chain molecule.
Isotone: One of a group of atoms or ions with nuclei that contain the same number of neutrons but different numbers of protons.
Isotonic: Refers to solutions that have equal osmotic pressure.
Isotopes: Two atoms having the same number of protons but different numbers of neutrons are said to be isotopes of each other.
Isotopic Abundance: The fraction of atoms of a given isotope in a sample of an element.
Isotopic Mass: The mass of a single atom of a given isotope, usually given in daltons.
Isotropic: Having identical values of a property in all crystallographic directions
ITO: Chemical formula for Indium Tin Oxide.
K: Potassium is a soft, silvery coloured metal, which like other members of the alkali group of metals, is extremely reactive.
K₂O: Chemical formula for Potassium Oxide.
K₂O₂: Chemical formula for Potassium Peroxide.
K₂S: Chemical formula for Potassium Sulphide.
Kalium: The old name for Potassium and from where the chemical symbol K was derived.
Kapok: Used as an insulating or flotation material it comes from the seed hairs of the kapok tree (Ceiba Pentranda).
KBr: Chemical formula for Potassium Bromide.
KC₂H₃O₂: Chemical formula for Potassium Acetate.
KCl: Chemical formula for Potassium Chloride.
Keir Metal: Brass containing 55% copper, 40% zinc and 5% iron. Patented in 1779 by James Keir (Chemist, Geologist, Industrialist and Inventor) and used for the manufacture of window frames.
Ketone: Compunds containing a carbonyl group (-CO-) attached to two hydrocarbon radicals. The simplest ketone is acetone (CH₃COCH₃).
KF: Chemical formula for Potassium Fluoride.
KI: Chemical formula for Potassium Iodide.
Kiln: A furnace in which ceramics are fired.
Kinetics: The study of how fast reactions occur.
kJ: An abbreviation of kilojoule, one thousand joules. The SI unit of energy is the joule.
KMnO₄: Potassium Manganate VII
KNO₃: Chemical formula for Potassium Nitrate.
KO₂: Chemical formula for Potassium Superoxide.
KOH: Potassium Hydroxide.
Kr: Krypton is a rare gaseous element.
Krypton: A rare gaseous element.
La: Lanthanum is a soft, ductile, white metallic element which oxidises rapidly in air.
La₂O₃: Chemical formula for Lanthanum III Oxide.
LaB₆: Chemical formula for Lanthanum Hexaboride.
LaBr₃: Chemical formula for Lanthanum III Bromide.
LaC₂: Chemical formula for Lanthanum Carbide.
LaCl₃: Chemical formula for Lanthanum III Chloride.
Lacquer: A fast-drying usually clear coating that is highly flammable and dries by solvent evaporation only.
Lactic Acid: C₃H₆O₃
Plays a role in various biochemical processes.
Langasite: Alternative name for Lanthanum Gallium Silicate.
Lanthana: Alternative name for Lanthanum III Oxide.
Lanthanide: Elements 57-70 are called lanthanides.
Lanthanide Contraction: An effect that causes sixth period elements with filled 4f subshells to be smaller than otherwise expected.
Lanthanum: A soft, ductile, white metallic element which oxidises rapidly in air.
Lanthanum Carbide: LaC₂
Used it to study the manufacture of certain types of superconductors and nanotubes.
Lanthanum Carbonate: La₂(CO₃)₃
An ore of lanthanum metal, along with monazite.
Lanthanum Gallium Silicate: A piezoelectric material, with no phase transitions up to its melting point of 1470 �C.
Lanthanum Hexaboride: LaB₆
Used in hot cathodes, either as a single crystal or as a coating deposited by physical vapor deposition.
Lanthanum III Bromide: LaBr₃
A colourless white powder used as a source of lanthanum in chemical synthesis.
Lanthanum III Chloride: LaCl₃
Used as a mild Lewis acid to perform chemical reactions that usually require acidic conditions, such as converting aldehydes to acetals, under nearly neutral conditions.
Lanthanum III Oxide: La₂O₃
Used at a laboratory level to develop ferroelectric and in optical materials.
Lanthanum Sesquioxide: Alternative name for Lanthanum III Oxide.
Lanthanum Strontium Cobalt Ferrite: Being investigated as a material for intermediate temperature solid oxide fuel cell cathodes and as a membrane material for separation of oxygen from air.
Lanthanum Strontium Manganite: Commonly used in as a cathode material in commercially produced solid oxide fuel cells.
Lanthanum Trichloride: Alternative name for Lanthanum III Chloride.
Lard Oil: An oil made from animal fats usually mixed with mineral oils to reduce its cost and improve its qualities. Used in engineering as a cutting oil.
Lattice: An orderly arrangement of atoms in a material.
Lattice Parameter: The combination of unit cell edge lengths and interaxial angles that defines the unit cell geometry.
Laughing Gas: Nitrous oxide, an anaesthetic.
Law of Combining Volumes: When gases react, they do so in a definite proportion by volume, if the volumes are measured at the same pressure and temperature.
Law of Conservation of Mass: There is no change in total mass during a chemical change.
Law of Definite Proportions: When two pure substances react to form a compound, they do so in a definite proportion by mass.
Law of Multiple Proportions: When one element can combine with another to form more than one compound, the mass ratios of the elements in the compounds are simple whole-number ratios of each other.
Lawrencium: The only known isotope has a half life of 8 seconds.
Le Chatelier′s Principle: Predicts that when a stress is applied to an equilibrium mixture, the equilibrium will shift to relieve the stress.
Lead: A soft, malleable and ductile metallic element that has been known of and used since prehistoric times.
Lead II Acetate: Pb(C₂H₃O₂)₂
Used as a reagent to make other lead compounds and as a fixative for some dyes.
Lead II Carbonate: PbCO₃
Decomposes readily into Lead II Oxide and carbon dioxide at 200�C and can be reduced to lead using carbon monoxide.
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