When metals react with water, _________ gas is formed.

Options

A. Oxygen
B. Hydrogen
C. Water
D. Both (a) and (b)

Answer

**Step-by-Step Solution:**

1. **Understanding the Reaction**: When metals react with water, they typically undergo a chemical reaction. This reaction can produce a metal hydroxide and a gas.

2. **Identifying the Gas**: In most cases, the gas produced when metals react with water is hydrogen gas. This is a common reaction for alkali metals such as sodium and potassium.

3. **Example Reaction**: For instance, when sodium (Na) reacts with water (H2O), it forms sodium hydroxide (NaOH) and hydrogen gas (H2). The chemical equation for this reaction can be written as:
\[ 2Na + 2H_2O \rightarrow 2NaOH + H_2 \]

4. **Conclusion**: Therefore, the gas that is formed when metals react with water is hydrogen gas.

5. **Final Answer**: The correct answer to the question is **Hydrogen**.

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