Atoms of the same element with the same number of protons but different number of neutrons.
The mass of an isotope relative to 1/12th the mass of an atom of carbon-12.
The weighted mean mass of an element is the weighted mean mass of an atom of an element, relative to one-twelfth (1/12) the mass of carbon-12.
The empirical formula is the simplest whole number ratio of atoms of each atom present in a compound.
A salt in which there are no waters of crystallisation.
A salt containing water of crystallisation.
An acid is a proton donor.
A base is a proton acceptor.
A compound where the hydrogen ions from an acid have been replaced by metal ions or ammonium ions.
The first ionisation energy is the amount of energy needed to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ atoms.
A region within an atom that is able to hold up to two electrons, with opposite spins.
The amount of substance which contains as many particles as there are carbon atoms in 12g of carbon-12 atoms.
The tendency to acquire a noble gas configuration.
A bond formed by the attraction between positive metal ions and a sea of delocalised electrons.
Electrostatic attraction between oppositely charged ions.
A shared pair of electrons.
A bond formed by a shared pair of electrons where both electrons have been donated by one atom.
The ability of an atom to attract electrons in a covalent bond.
The repeating pattern of properties shown across different periods.
A reaction in which the same element is both oxidised and reduced.
A three dimensional structure of oppositely charged ions held together by strong ionic bonds.