Give any two examples of superconductor.

Explanation

### Step-by-Step Text Solution

1. **Understanding Superconductors**:
- A superconductor is a material that can conduct electricity without any resistance. This phenomenon occurs when the material is cooled below a certain temperature known as the critical temperature.

2. **Example 1 - Mercury**:
- One example of a superconductor is **mercury**.
- The critical temperature for mercury is **4.2 Kelvin**.
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