How many moles of magnesium oxide are formed when 4 moles of magnesium react with oxygen? this is the formula for the reaction: ?

Mg + O2(o is a diatomic element)⇒ Mg O(UNBALANCED)
Mg is +2, o is -2, so MgO is the product.
BALANCED EQUATION :  2Mg + O2 ⇒ 2MgO
There are 4 moles of magnesium, so there should be 4/2*2=4 moles of oxygen, and the product will have 4+4=8 moles.
there will be 8 moles of magnesium oxide.