http://www.ck12.org Chapter 27. Glossary
alkyne
A hydrocarbon with one or more carbon-carbon triple covalent bonds.
alloy
A mixture composed of two or more elements, at least one of which is a metal.
alpha particle (α)
A helium nucleus, two protons and two neutrons, which is emitted during some types of radioactive decay.
alkali metal
An element in Group 1 (lithium, sodium, potassium, rubidium, cesium, and francium).
alkaline earth metal
An element in Group 2 (beryllium, magnesium, calcium, strontium, barium, and radium).
amine
An organic compound that can be considered to be a derivative of ammonia (NH 3 ).
amino acid
A compound that contains both an amino group (−NH 2 ) and a carboxyl group (−COOH) in the same
molecule.
amorphous solid
A solid that lacks an ordered internal structure.
amphoteric
A substance that is capable of acting as either an acid or a base by donating or accepting hydrogen ions.
analytical chemistry
A branch of chemistry that is the study of the composition of matter, focusing on separating, identifying, and
quantifying chemicals in samples of matter
angular momentum quantum number
Indicates the shape of the orbital, symbolized by the letterl.
anion
A negatively charged ion.
anode
The electrode at which oxidation occurs.
applied chemistry
Chemistry that is directed toward a specific practical goal or application.
aqueous solution
Water that contains one or more dissolved substances.
aromatic hydrocarbon
A hydrocarbon that contains one or more benzene rings.
Arrhenius acid
A compound which ionizes to yield hydrogen ions (H+) in aqueous solution.
Arrhenius base
A compound which ionizes to yield hydroxide ions (OH−) in aqueous solution.
artificial transmutation
The bombardment of stable nuclei with charged or uncharged particles in order to cause a nuclear reaction.
atmospheric pressure
The pressure exerted by gas particles in Earth’s atmosphere as those particles collide with objects.
atom
The smallest particle of an element that retains the properties of that element.
atomic emission spectrum
A pattern of lines formed when light passes through a prism to separate it into the different frequencies of
light it contains.
atomic mass
The weighted average of the atomic masses of the naturally occurring isotopes of that element.
atomic mass unit
Defined as a mass equal to one twelfth the mass of an atom of carbon-12.