## The mole and the Avogadro constant

The Avogadro constant as the number of particles in a mole.

The mole as applied to electrons, atoms, molecules, ions, formulas and equations.

The concentration of a substance in solution, measured in mol dm^{-3}.

[Students will not be expected to recall the value of the Avogadro constant]

**Assessment and practical skills**

Students should be able to carry out calculations:

• using the Avogadro constant

• using mass of substance, M_{r } and amount in moles

• using concentration, volume and amount of substance in a solution.