Which is the correct formula for magnesium oxide?
Mg2O\mathrm{Mg_{2}O}Mg2O
MgO2\mathrm{MgO_{2}}MgO2
MgO\mathrm{MgO}MgO
Mg2O2\mathrm{Mg_{2}O_{2}}Mg2O2
230 exam-style questions on Edexcel GCSE Chemistry 1.1 Formulae, equations and hazards, covering 1.1.1 Formulae, word and balanced equations, 1.1.2 Balanced ionic equations, and 1.1.3 Hazard symbols and risk in practical work. Each one has a worked solution and a mark scheme showing where the marks go.