Evaporation

• Evaporation is the escape of energetic particles from the surface of a liquid
• If more energetic particles escape, the liquid contains few high energy particles and more low energy particles so the average temperature decreases.

  
• A body in contact with an evaporating liquid will subsequently cool.
• Evaporation can be accelerated by:

  • Increasing temperature: more particles have energy to escape
  • Increasing surface area: more molecules are close to the surface
  • Reduce humidity level in air (draught): if the air is less humid, fewer particles are condensing.