Which of the following metals absorbs hydrogen ?

Options

A. Zn
B. Pd
C. Al
D. K

Answer

To determine which of the following metals absorbs hydrogen, we will analyze each option provided: Zinc, Palladium, Aluminium, and Potassium.

### Step-by-Step Solution:

1. **Understanding Hydrogen Absorption**:
- Some metals can absorb hydrogen gas and are often used as catalysts in hydrogenation reactions. This property is important in various chemical processes.

2. **Evaluating Each Metal**:
- **Zinc (Zn)**: Zinc is not known for its ability to absorb hydrogen gas significantly. It can react with acids to produce hydrogen but does not act as a catalyst for hydrogenation.
- **Palladium (Pd)**: Palladium is a well-known catalyst that can absorb hydrogen gas. It is widely used in hydrogenation reactions due to its ability to dissociate and absorb hydrogen on its surface.
- **Aluminium (Al)**: Aluminium can react with water or acids to produce hydrogen, but it does not absorb hydrogen gas in the same way as palladium.
- **Potassium (K)**: Potassium is a highly reactive alkali metal that does not absorb hydrogen gas. Instead, it reacts vigorously with water.

3. **Conclusion**:
- Among the given options, **Palladium** is the metal that absorbs hydrogen. Therefore, the correct answer is **Palladium (Option B)**.

### Final Answer:
**Palladium absorbs hydrogen.**