Britannica
Sources used in this answer
Which substance is oxidized when magnesium burns in oxygen?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
When magnesium burns in oxygen, the magnesium is the substance that is oxidized.1
In this oxidation-reduction reaction, each magnesium atom gives up two electrons to the oxygen, which increases the magnesium's oxidation state. Conversely, the oxygen atoms accept these electrons and are reduced, forming the ionic compound magnesium oxide (MgO).1