How to react magnesium with oxygen

Write a hypothesis

Roll up the coil of magnesium

Weigh the magnesium in the crucible

This is how much it weighed

Place the crucible on the gorse. Heat the magnesium in the pot

Heat until the magnesium has stopped reacting

Weigh the crucible and magnesium after the reaction has stopped

This is how much it weighed afterwards

These are our final results. The magnesium should have gained mass but, instead lost it.