1.17 + 1.18 understand the use of the term mole to represent the amount of substance and know the term 'Avogadro Number'

Moles

The mole is a measure of the amount of substance.

The mole (1 mol) is the amount of substance that contains:
 6 x 10^{23 particles of the substance.}

This is known as the Avogadro Number.

e.g.

1 mol of Sodium (Na) contains 6 x 10^{23 atoms of sodium.}