Evaporation is the process of conversion of

Options

A. a liquid to its gaseous state below the boiling point of the substance.
B. a liquid to its gaseous state at the boiling point of the substance.
C. a solid to its liquid state at the melting point of the substance.
D. a solid to its liquid state below the melting point of the substance.

Explanation

**Step-by-Step Solution:**

1. **Understanding Evaporation:**
- Evaporation is a process that involves the transformation of a liquid into a gas. This occurs when molecules at the surface of the liquid gain enough energy to break free from the liquid state.

2. **Key Characteristics of Evaporation:**
- It is important to note that evaporation can occur at any temperature, not just at the boiling point of the liquid. This means that even if the liquid is below its boiling point, it can still evaporate.

3. **Surface Phenomenon:**
- Evaporation primarily occurs at the surface of the liquid. Only the molecules at the surface can escape into the vapor phase, which distinguishes it from boiling, where the entire liquid is involved.

4. **Influencing Factors:**
- Factors such as temperature and humidity play a significant role in the rate of evaporation. For instance, higher temperatures increase the energy of the molecules, leading to faster evaporation.

5. **Example of Evaporation:**
- A common example is when water is left out in the sun. The heat from the sunlight increases the temperature of the water, causing it to evaporate into water vapor.

6. **Conclusion:**
- Therefore, we can conclude that evaporation is the process of conversion of a liquid to its gaseous state below the boiling point of the substance.

**Final Answer:**
Evaporation is the process of conversion of a liquid to its gaseous state below the boiling point of the substance.

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