When magnesium ribbon burns in oxygen, a vigorous exothermic reaction takes place, resulting in the formation of magnesium oxide (MgO). The chemical equation for this reaction is:
2Mg(s) + O₂(g) → 2MgO(s)
The magnesium atoms react with oxygen molecules to produce magnesium oxide. The combustion is highly exothermic, releasing a significant amount of heat and intense white light. The bright white light produced during the reaction is characteristic of burning magnesium, making it useful in applications like photography and fireworks.