oxidation or reduction?? either??

Question

For the following balanced chemical equation:

     2 Mg _(s)   +  O_{2 (g)}   →  2 MgO _(s)   

3.6 moles of Mg are put into a reaction container with 1.4 moles of O₂ gas. The reaction is run until all of the oxygen gas is used. How much MgO is made?

Answer 1

1.4 mol O₂ x 2 mol MgO/mol O₂ = 2.8 moles MgO produced