Which noble gas was discovered in chromosphere?

Options

A. He
B. Ar
C. Xe
D. Rn

Answer

**Step-by-Step Solution:**

1. **Identify the Context**: The question asks about a noble gas discovered in the chromosphere of the Sun. The chromosphere is a layer of the Sun's atmosphere.

2. **Historical Reference**: In 1868, a scientist named Joseph Norman Lockyer observed the chromosphere during a solar eclipse.

3. **Discovery of the Element**: Lockyer discovered a new element while studying the chromosphere. This element was not known on Earth at the time.

4. **Naming the Element**: The element discovered by Lockyer was later named "helium." The name is derived from "Helios," the Greek word for the Sun.

5. **Classification of Helium**: Helium is classified as a noble gas. Noble gases are known for their lack of reactivity due to having a full valence shell of electrons.

6. **Conclusion**: Therefore, the noble gas discovered in the chromosphere is helium.

**Final Answer**: Helium

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