How does magnesium react with oxygen to form magnesium oxide?

The reaction between magnesium and oxygen is a classic example of an oxidation-reduction (redox) reaction, which involves the transfer of electrons from a reducing agent to an oxidizing agent.1

When magnesium burns in oxygen, it forms magnesium oxide (MgO), an ionic compound composed of ${\text{Mg}}^{2+}$ and ${\text{O}}^{2-}$ ions. The process occurs as follows:1

• Oxidation: Each magnesium atom gives up two electrons, becoming oxidized.1
• Reduction: Each oxygen atom accepts those two electrons, becoming reduced.1

This electron transfer increases the charge on the magnesium atom and decreases the charge on the oxygen atom, resulting in the formation of the stable ionic product. While magnesium oxide can also be produced through other industrial methods, such as roasting magnesium carbonate or magnesium hydroxide, the direct combustion of magnesium in oxygen is a fundamental demonstration of redox chemistry.12