How does electrical conductivity vary in metals with temperature?

Explanation

### Step-by-Step Solution:

1. **Understanding Electrical Conductivity in Metals**:
- Metals are known as conductors due to the presence of free electrons that can move easily between the conduction band and the valence band. This movement of electrons is what allows metals to conduct electricity.

2. **Effect of Temperature on Electron Movement**:
- As the temperature of a metal increases, the thermal energy causes the atoms in the metal to vibrate more vigorously. This increased vibration affects the movement of free electrons.

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