1. EvaporationEvaporationEvaporationEvaporation F. 3A Winnie Chan (6) Lydia Chan (7) Vikki Chan (8) Stephanie Cheung (9) Vivian Chiu (10)

2. What is evaporation? The water changes into water vapour in a process called evaporation.The water changes into water vapour in a process called evaporation. Evaporation is the change of state from liquid to gas below the boiling point. Boiling only takes place at the boiling point, but evaporation can take place in any temperatures below the boiling point. In addition, evaporation only takes place on the surface of a liquid, where as boiling takes place everywhere within the liquid.Evaporation is the change of state from liquid to gas below the boiling point. Boiling only takes place at the boiling point, but evaporation can take place in any temperatures below the boiling point. In addition, evaporation only takes place on the surface of a liquid, where as boiling takes place everywhere within the liquid.

3. The conversion of water from a liquid into a gas Water is transferred from the surface to the atmosphere through evaporation, the process by which water changes from a liquid to a gas.Water is transferred from the surface to the atmosphere through evaporation, the process by which water changes from a liquid to a gas.

4. Approximately 80% of all evaporation is from the oceans, with the remaining 20% coming from inland water and vegetation. Winds transport the evaporated water around the globe, influencing the humidity of the air throughout the world.Approximately 80% of all evaporation is from the oceans, with the remaining 20% coming from inland water and vegetation. Winds transport the evaporated water around the globe, influencing the humidity of the air throughout the world. Most evaporated water exists as a gas outside of clouds and evaporation is more intense in the presence of warmer temperatures. This is shown in the image above, where the strongest evaporation was occurring over the oceans and near the equatorMost evaporated water exists as a gas outside of clouds and evaporation is more intense in the presence of warmer temperatures. This is shown in the image above, where the strongest evaporation was occurring over the oceans and near the equator

5. Microscopic interpretation of evaporation Inside a liquid, the distribution of kinetic energy of the particles is random and some has higher and some lower kinetic energies.Inside a liquid, the distribution of kinetic energy of the particles is random and some has higher and some lower kinetic energies. The energetic particles have enough energy to overcome the attractive forces between them and leave the liquid through the liquid surface.The energetic particles have enough energy to overcome the attractive forces between them and leave the liquid through the liquid surface. The particles that leave the liquid are the high-energy particles,The particles that leave the liquid are the high-energy particles, The average kinetic energy of the liquid particles decreases the temperature of the liquid will decreases.The average kinetic energy of the liquid particles decreases the temperature of the liquid will decreases. The liquid cools down during evaporation.The liquid cools down during evaporation. The evaporated vapour takes away latent heat and cools down the liquid.The evaporated vapour takes away latent heat and cools down the liquid.

6. Sweating helps to maintain our body temperature normal through evaporation. Sweat is mainly water and when it evaporates, it takes away latent heat of vaporization from your body. When you are exercising vigorously, your body needs to lose more heat to maintain the normal body temperature, so it produces extra sweat. Dogs have no sweat gland, they cool themselves by panting.Sweating helps to maintain our body temperature normal through evaporation. Sweat is mainly water and when it evaporates, it takes away latent heat of vaporization from your body. When you are exercising vigorously, your body needs to lose more heat to maintain the normal body temperature, so it produces extra sweat. Dogs have no sweat gland, they cool themselves by panting. Cooling effect of evaporation

7. Rate of evaporation The wind carries the water vapour away and increases the rate of evaporation of sweat from your body. In fact, there are many ways to increase the rate of evaporation of a liquid: The wind carries the water vapour away and increases the rate of evaporation of sweat from your body. In fact, there are many ways to increase the rate of evaporation of a liquid: 1.Increase the temperature of the liquid. One example is that a puddle of water will dry up faster under the sun than in the shades. 2.Increase the surface area of the liquid exposed. For example, spilled water evaporates faster than when it is in a glass. 3.Increase the movement of air near the surface of the liquid. For example, clothes dry faster on a windy day. 4.Decrease the amount of vapour in the surrounding air. For example, clothes dry faster on days with low humidity than on days with high humidity.

8. ResourcesResourcesResourcesResources http://ww2010.atmos.uiuc.edu/(Gh)/guide s/mtr/hyd/evap.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/guide s/mtr/hyd/evap.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/guide s/mtr/hyd/evap.rxmlhttp://ww2010.atmos.uiuc.edu/(Gh)/guide s/mtr/hyd/evap.rxml http://www.phy.cuhk.edu.hk/contextual/h eat/cha/evapo01_e.htmlhttp://www.phy.cuhk.edu.hk/contextual/h eat/cha/evapo01_e.htmlhttp://www.phy.cuhk.edu.hk/contextual/h eat/cha/evapo01_e.htmlhttp://www.phy.cuhk.edu.hk/contextual/h eat/cha/evapo01_e.html

9. Thank You!!! XP