Aluminium ions are Al3+\mathrm{Al^{3+}}Al3+ and oxide ions are O2−\mathrm{O^{2-}}O2−. Which formula has no overall charge?
AlO3\mathrm{AlO_{3}}AlO3
Al2O\mathrm{Al_{2}O}Al2O
Al2O3\mathrm{Al_{2}O_{3}}Al2O3
AlO\mathrm{AlO}AlO
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.