MODEL RELEASED. Oxidation of magnesium. Students observing the oxidation of magnesium metal (in the crucible, white, lower centre) by a bunsen flame. The magnesium (Mg) will turn to magnesium oxide (MgO) as it reacts with the oxygen (O2) in the atmosphere. The equation for the reaction is: 2 Mg + O2 ----> 2 MgO The rest of the experiment will involve the weighing of the magnesium oxide and comparing the mass with that of the pre-weighed magnesium. The increase in mass will demonstrate that a reaction has occurred, rather than a decomposition.