Hydrogen burns in air with a

Options

A. light bluish flame
B. yellow flame
C. cimson red flame
D. green flame.

Explanation

To answer the question "Hydrogen burns in air with a...", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: The combustion of hydrogen can be represented by the chemical equation:
\[ \text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O} \]

2. **Balance the Reaction**: To balance the equation, we need to ensure that the number of atoms of each element on the reactant side equals the number on the product side. The balanced equation is:
\[ 2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O} \]

3. **Understand the Combustion Process**: Combustion is a chemical reaction that occurs when a substance reacts with oxygen, producing heat and light. In this case, hydrogen reacts with oxygen in the air.

4. **Determine the Flame Color**: When hydrogen burns in air, it produces a flame. The characteristic color of the flame produced by burning hydrogen is pale blue or light blue. This flame is often nearly invisible in daylight.

5. **Consider Impurities**: If there are impurities present in the air, the flame may appear yellow due to the combustion of these impurities. However, the pure hydrogen flame remains light blue.

6. **Conclusion**: Based on the above information, we can conclude that hydrogen burns in air with a pale blue flame.

### Final Answer:
Hydrogen burns in air with a **pale blue flame**.

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