MgO is produced when magnesium is undergo combustion
that is 2 Mg +O2 = 2MgO
2 mole of magnesium (Mg) during combustion reaction react with 1 mole of oxygen (O2) to form 2 moles of magnesium oxide (MgO). a combustion reaction is a reaction by which a substance react with oxygen and it is always exothermic ( releases heat energy)