Base

A reference value.

Chemistry

• A compound that reacts with an acid to form a salt .
• Substance which gives off hydroxide ions (OH^-) in solution (Arrhenius).
• A molecule or ion that captures hydrogen ions (Bronsted-Lowry).
• A molecule or ion that donates an electron pair to form a chemical bond (Lewis).

Electronics

The region between the emitter and collector of a transistor that receives minority carriers injected from the emitter. It is the element that corresponds to the control grid of an electron tube.

Mathematics

In the expression x^y, x is called the base and y is the exponent.

See also: Alkaline, Brösted Base, Buffer Solutions, Conjugate Acid, Conjugate Base, Equivalence Point, Exponent, pH, pOH, Weak Bases.