Define non renewable energy?

Answer

### Step-by-Step Solution:

1. **Definition of Non-Renewable Energy**:
Non-renewable energy refers to energy sources that cannot be replenished or regenerated within a human timescale. Once these energy sources are depleted, they take millions of years to form again.

2. **Characteristics of Non-Renewable Energy**:
- **Finite Supply**: Non-renewable energy sources are limited in quantity. Once they are used up, they cannot be replaced in a short period.
- **Long Formation Period**: The formation of these energy sources takes thousands to millions of years, making them non-renewable in practical terms.

3. **Examples of Non-Renewable Energy**:
- **Coal**: Formed from the remains of ancient plants that died millions of years ago.
- **Oil**: Another fossil fuel that is formed from the remains of marine organisms over millions of years.
- **Natural Gas**: Similar to oil, it is formed from the remains of ancient organisms and is also a fossil fuel.
- **Nuclear Energy**: Although it is derived from uranium, which is a finite resource, it is classified as non-renewable because once the uranium is used, it cannot be replaced quickly.

4. **Conservation of Non-Renewable Energy**:
Due to their finite nature, it is crucial to use non-renewable energy sources wisely and conserve them for future generations.