The elements which are radioactive and have been named after the name of planet are

Options

A. Hg
B. Po
C. Pu
D. Ra

Answer

To solve the question regarding the radioactive elements named after planets, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify which of the given elements is radioactive and has been named after a planet.

2. **Examine the Options**: The options provided are:
- Hg (Mercury)
- Po (Polonium)
- Pu (Plutonium)
- Ra (Radium)

3. **Identify Radioactive Elements**:
- **Hg (Mercury)**: This is not radioactive; it is a stable element.
- **Po (Polonium)**: This is radioactive, but it is not named after a planet.
- **Pu (Plutonium)**: This is radioactive and is named after the planet Pluto.
- **Ra (Radium)**: This is also radioactive, but it is not named after a planet.

4. **Conclusion**: The only element that is both radioactive and named after a planet is **Plutonium (Pu)**.

### Final Answer:
The element which is radioactive and has been named after the name of a planet is **Plutonium (Pu)**.

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