Which balances the equation Mg + O2 → MgO?

Question

Mg + 2O2 → 4MgO
2Mg + 2O2 → 2MgO
2Mg + O2 → 2MgO
2Mg + 2O2 → 4MgO

Answer 1

To balance the equation \( \text{Mg} + \text{O}_2 \rightarrow \text{MgO} \), we need to ensure that the number of atoms of each element is the same on both sides of the equation.

Let's analyze the given options:

1. Mg + 2O2 → 4MgO
   This is incorrect because it would imply 2 oxygen molecules producing 4 magnesium oxides, which doesn't balance.

2. 2Mg + 2O2 → 2MgO
   This is incorrect because there are more oxygen atoms on the left side than on the right side.

3. 2Mg + O2 → 2MgO
   This is the correct balance. On the left side, there are 2 magnesium atoms and 2 oxygen atoms (from \( \text{O}_2 \)), which matches the right side with 2 magnesium atoms and 2 oxygen atoms (from 2 \( \text{MgO} \)).

4. 2Mg + 2O2 → 4MgO
   This is incorrect because again it implies there are too many oxygen atoms on the left producing too many magnesium oxides on the right.

Therefore, the correct balanced equation is: 2Mg + O2 → 2MgO.