The correct option is (b).
Explanation
Evaporation is a surface phenomenon in which a liquid changes into a vapor state at any temperature below its boiling point. It involves the escape of molecules with higher kinetic energy from the surface of the liquid.
Statement-wise Analysis:
- Statement 1 is Incorrect. Evaporation occurs at all temperatures, not just at the boiling point (100°C for water). Boiling is a bulk phenomenon that occurs at a specific temperature, whereas evaporation is a continuous process happening at the surface of the liquid regardless of temperature.
- Statement 2 is Correct. Evaporation causes cooling. The particles of the liquid absorb energy from the surroundings to regain the energy lost during evaporation (latent heat of vaporization). This absorption of energy from the surroundings results in a decrease in temperature of the immediate environment.
- Statement 3 is Incorrect. Evaporation is a surface phenomenon. The rate of evaporation is directly proportional to the surface area. If the surface area is increased, more particles are exposed to the atmosphere, leading to a faster rate of evaporation.
Key Takeaway:
Evaporation occurs at any temperature below the boiling point and causes cooling. Its rate is increased by an increase in surface area, temperature, and wind speed, but decreased by an increase in humidity.