1.21 Write word equations and balanced chemical equations to represent the reactions studied in this specification

The equation must have at least one reactant (usually 2 though), and a product (again, usually two), and there must be the same number of atoms on both sides - that’s where the balancing comes in.

i.e. H₂O_(l) → H₂O_(g) This equation is balanced (it shows water going from one state to another)

Na_(s) + H₂SO_4(aq) → NaSO_4(aq) + 2H_(g) This equation had to be balanced. You do this by putting a big number in front of the element. DO NOT add a small number because you will lose marks for that.

You don't need to balance word equations but for the reaction above, it would be:

Sodium + Sulphuric acid → Sodium Sulphate + Hydrogen gas