Final answer:
Magnesium, when heated, reacts with oxygen in the air to form a fine powder of magnesium oxide (MgO), represented by the chemical equation 2Mg (s) + O₂(g) → 2MgO (s). This exothermic reaction releases a bright white flame and heat.
Step-by-step explanation:
Magnesium reacts with oxygen in the air under specific conditions to produce magnesium oxide. This reaction occurs as a type of combination reaction, where magnesium gets oxidized when heated. When magnesium reacts with oxygen, it loses electrons to oxygen atoms, resulting in the formation of a fine powder known as magnesium oxide (MgO).
The chemical equation representing this reaction is:
- 2Mg (s) + O₂(g) → 2MgO (s)
This reaction is highly exothermic, producing a bright white flame and releasing a significant amount of heat. A layer of magnesium oxycarbonate usually forms on the surface of magnesium metal when it's exposed to air, due to the reaction with carbon dioxide, which can inhibit further reaction unless the metal is heated sufficiently to ignite and combine with oxygen.