What happens when:
Methane burns in air.

Explanation

### Step-by-Step Solution:

1. **Identify the Reactants**: When methane (CH₄) burns in air, the primary reactants involved are methane and oxygen (O₂).

2. **Write the Chemical Equation**: The combustion of methane can be represented by the following balanced chemical equation:
\[ CH₄ + 2O₂ \rightarrow CO₂ + 2H₂O \]
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