Ionisation energy

Ionisation energy

The energy required to remove 1 mole of electrons from 1 mole of gaseous substance to form 1 mole of gaseous ion

First ionisation energy

The energy required to remove 1 electron from 1 mole of gaseous substance to from 1 mole of gaseous 1+ ion

Second ionisation energy

The energy required to remove 1 electron from 1 mole of gaseous 1+ ions to from 1 mole of gaseous 2+ ions

Third ionisation energy

The energy required to remove 1 electron from 1 mole of gaseous 2+ ions to from 1 mole of gaseous 3+ ions

Fourth ionisation energy

The energy required to remove 1 electron from 1 mole of gaseous 3+ ions to from 1 mole of gaseous 4+ ions

Relative Isotopic Mass

The average mass of an isotope relative to the 1/12 of the mass of an atom of carbon 12

Relative Atomic Mass

The weighed mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12