Definitions

Atoms of the same element with the same number of protons but different number of neutrons.

The mass of an isotope compared with 1/12 of the mass of an atom of carbon-12.

The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12.

6.02 x 10^23, the number of atoms per mole of carbon-12.

The simplest whole number ratio of atoms of each element present in a compound.

The number and type of atoms of each element in a molecule.

The reactant that is not in excess, which will be used up first and stop the reaction.

A species that releases H+ ions in aqueous solution.

A compound that neutralises an acid to form a salt.

A type of base that dissolves in water and releases OH- (hydroxide) ions in aqueous solution.

An acid that completely dissociates in solution and release all H+ ions.

An acid that partially dissociates in solution and releases some H+ ions.

The reaction of: 1. H+ and OH– to form H2O 2. acid and base to form salt

A technique used to measure the volume of one solution that reacts exactly with another solution.

A solution of known concentration

The number of electrons involved in bonding to a different element.

Loss of electrons and an increase in oxidation number.

Gain of electrons and a decrease in oxidation number.

A reaction that involves both oxidation and reduction.

When the same element is both oxidised and reduced during a reaction.

A group of atomic orbitals with the same principal quantum number N.

A region around the nucleus that can hold up to two electrons, with opposite spins.

Electrostatic attraction between positive and negative ions.

A three-dimensional structure of oppositely charged ions that are strongly attracted in all directions, bonded together by strong ionic bonds.