What is the conversion of water into vapour is called ?

Options

A. Natural
B. Physical
C. Chemical
D. Biological

Explanation

**Step-by-Step Solution:**

1. **Understanding the Process**: The question asks about the conversion of water into vapor. This process involves a change in the state of matter.

2. **Identifying the Type of Change**: There are two main types of changes: physical changes and chemical changes.
- **Physical Change**: This type of change is generally reversible and involves a change in the state of matter (solid, liquid, gas) without altering the chemical composition of the substance.
- **Chemical Change**: This type of change is generally irreversible and involves a change in the chemical composition of the substance.

3. **Recognizing the Conversion**: The conversion of water (liquid) into vapor (gas) is a physical change. This is because:
- Water can be converted back into liquid form (condensation).
- The chemical composition of water (H2O) remains the same during this process.

4. **Conclusion**: Therefore, the conversion of water into vapor is called **evaporation** (or vaporization), and it is classified as a physical change.

**Final Answer**: The conversion of water into vapor is called **evaporation**.

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