Atoms and Ions

The characteristic of an element being able to exist in more than one crystal structure,

depending on temperature and pressure

A material that does not have long-range order for the arrangement of its

atoms

A negatively charged ion produced when an atom, usually of a non-metal, accepts one or

more electrons.

The mass of the Avogadro constant of atoms, g/mol. Normally, this is the average

number of protons and neutrons in the atom. Also called the atomic weight.

The mass of an atom expressed as 1/12 the mass of a carbon atom with twelve

nucleons.

The number of protons in an atom

A graphical device used to determine the order in which the energy levels of

quantum shells are filled by electrons.

The number of atoms or molecules in a mole. The Avogadro constant is

6.022 x 10^23 per mole.

A quantum number that designates different energy levels in principal shells. Also called the secondary quantum number.

The energy required to separate two atoms from their equilibrium spacing to an infinite distance apart. The binding energy is a measure of the strength of the bond between two atoms.