What happens when following elements are made to react with hydrogen.
State the conditions required, if any.
Oxygen

Explanation

**Step-by-Step Solution:**

1. **Identify the Reaction**: When hydrogen (H2) reacts with oxygen (O2), it forms water (H2O). The balanced chemical equation for this reaction is:
\[ 2H_2 + O_2 \rightarrow 2H_2O \]

2. **Conditions Required**: The reaction between hydrogen and oxygen requires specific conditions to occur. The primary condition is the presence of an ignition source, such as an electric spark or flame, to initiate the reaction.
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