Which equation is correctly balanced for aluminium reacting with oxygen?
Al+O2→Al2O3\mathrm{Al} + \mathrm{O_{2}} \rightarrow \mathrm{Al_{2}O_{3}}Al+O2→Al2O3
2Al+O2→Al2O32\mathrm{Al} + \mathrm{O_{2}} \rightarrow \mathrm{Al_{2}O_{3}}2Al+O2→Al2O3
4Al+3O2→2Al2O34\mathrm{Al} + 3\mathrm{O_{2}} \rightarrow 2\mathrm{Al_{2}O_{3}}4Al+3O2→2Al2O3
4Al+O2→2Al2O34\mathrm{Al} + \mathrm{O_{2}} \rightarrow 2\mathrm{Al_{2}O_{3}}4Al+O2→2Al2O3
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.