A student burns a piece of magnesium ribbon in air. Magnesium oxide is produced.
Balance the equation for this reaction.
Mg+O2→MgO\text{Mg} + \text{O}_2 \rightarrow \text{MgO}Mg+O2→MgO
State the law of conservation of mass.
40 exam-style questions on AQA GCSE Chemistry 3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations, covering 3.1.1 Conservation of mass and balanced chemical equations, 3.1.2 Relative formula mass, 3.1.3 Mass changes when a reactant or product is a gas, and 3.1.4 Chemical measurements. Each one has a worked solution and a mark scheme showing where the marks go.