moles

Relative atomic mass (Ar)

Average mass of an atom of an element relative to one twelfth of the mass of a carbon-12 atom

For atoms

Relative molecular mass (MR)

Mass of a molecule relative to one twelfth of the mass of a carbon 12 atom

For molecules

Relative formula mass

Mass of one formula unit of an ionic compound relative to one twelfth of the mass of a carbon 12 atom

Mole

• symbol : mol

• Unit of measurement for very small particles such as atoms. Molecules , ions and electrons

Avagardos constant

6.02× 10²³

Molar volume of gas

One mole of any gas always occupies a volume of 22.7dm³ at standard temperature and pressure (STP)

Concentration of solution

The amount of solute in 1dm³ of a solution

Empirical formula

Simplest ratio of the atoms

Molecular formula

Shows exact number of atoms of different elements in one molecule

Limiting reagent

The reactant that is completely used up when the reaction is completed