Question

Can magnesium burn without oxygen?

Answer 1

• As a rule, nothing can “burn” without Oxygen. However, different things may happen to depend on if there is free Oxygen ($O_2$) present. Most things require free $O_2$ in the air or fed from a tank to burn. But Magnesium has the unique ability to react with things around it such as $C{O}_2$ (Carbon Dioxide) or $H_{2}O$ (water) to extract Oxygen for burning.
  
• So, while Magnesium can burn in an environment devoid of free $O_2$, it cannot burn in an environment completely devoid of the Oxygen element.
  
• Hence the answer is yes.