Glossary

Absolute zero

Absolute    zero

The temperature at  which   all substances  have    no  thermal energy; 0   K   or  –273.15°C.

Absorption spectrum

Absorption spectrum
The series of discrete lines at characteristic frequencies representing the energy required to
make an atom undergo a transition to a higher energy state.

Acid

Acid
A species that donates hydrogen ions and/or accepts electrons. See Acidic solution; Arrhenius
acid; Brønsted-Lowry acid; Lewis acid.

Acid dissociation constant (Ka)

Acid    dissociation    constant    (Ka)

The equilibrium constant    that    measures    the degree  of  dissociation    for an  acid    under   specific

conditions. For an acid HA:

Acidic anhydride

Acidic  anhydride

An  oxide   that    dissolves   in  water   to  form    an  acidic  solution.