Question

Question
Which equation represents the balanced chemical equation for the synthesis reaction that forms magnesium oxide (MgO)?
Responses

2Mg + 3O2→3MgO
2 uppercase M lowercase g plus 3 uppercase O subscript 2 end subscript rightwards arrow 3 uppercase M lowercase g uppercase O

2Mg + 2O2→2MgO
2 uppercase M lowercase g plus 2 uppercase O subscript 2 end subscript rightwards arrow 2 uppercase M lowercase g uppercase O

Mg + O2→MgO
uppercase M lowercase g plus uppercase O subscript 2 end subscript rightwards arrow uppercase M lowercase g uppercase O

2Mg + O2→2MgO

Answer 1

Correct answer: 2Mg + O2 → 2MgO

Reason: Two Mg atoms react with one O2 molecule (2 oxygen atoms) to give two MgO units, so both Mg and O are balanced.