Why do Zr and Hf exhibit similar properties?

Explanation

### Step-by-Step Solution:

1. **Understanding the Elements**:
- Zirconium (Zr) and Hafnium (Hf) are both transition metals found in Group 4 of the periodic table. Zr is in the 5th period, while Hf is in the 6th period.

**Hint**: Identify the position of the elements in the periodic table to understand their similarities.

2. **Lanthanide Contraction**:
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