In partnership with the Society of Biology, Royal Society of Chemistry, and Institute of Physics

Magnesium and carbon dioxide

This lesson is designed to exemplify an argumentation approach to practical work, using a ‘predict, observe, explain’ framework.

When burning magnesium is placed into a gas jar of carbon dioxide it is not extinguished but burns more brightly. This is due to the relative positions of magnesium and carbon in the reactivity series. The result surprises many students who know that carbon dioxide puts out fires – and is in many fire extinguishers.

This lesson allows students to argue about what they think will happen in the reaction and to draw up competing theories. They then observe the reaction and write an explanation for what they have seen.

Download resources

Resources for this lesson comprise: two student sheets; teacher guidance; practical guidance; evidence cards; and a presentation. You should also read our standard health & safety guidance.

Quick start guide

For support in using the argumentation approach and to find out more about the research behind it, refer to our quick start guide