` 2Mg + O_(2) to 2MgO`

Explanation

To analyze the reaction \(2Mg + O_2 \rightarrow 2MgO\) and determine which substance is oxidized and which is reduced, we can follow these steps:

### Step 1: Identify the Reactants and Products
The reactants in this reaction are magnesium (Mg) and oxygen (O\(_2\)), and the product is magnesium oxide (MgO).

### Step 2: Determine the Oxidation States
- **Magnesium (Mg)**: In its elemental form (as a reactant), the oxidation state of magnesium is 0.
- **Oxygen (O\(_2\))**: In its elemental form (as a reactant), the oxidation state of oxygen is also 0.
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