Grade 10 · Theory
Representing chemical change
Matter and classification · about 3 min
A balanced equation is the sentence of chemistry: it must obey conservation of mass.
Key points- Reactants on the left, products on the right, separated by an arrow.
- Balance by changing COEFFICIENTS only — never the subscripts inside a formula.
- Include state symbols: (s) solid, (l) liquid, (g) gas, (aq) aqueous.
- Count each element on both sides to confirm the balance.
- Coefficient — the number in front of a formula.
- Aqueous — dissolved in water.
EXAM TIP
balance metals first, then non-metals, and leave hydrogen and oxygen for last — it converges much faster.