Evaporation of water from the surface of the skin causes cooling. Describe, using ideas about particles, how evaporation causes cooling.

1. (a)(i)Evaporation of water from the surface of the skin causes cooling. Describe, using ideas about particles, how evaporation causes cooling.[2]
2. (a)(ii)State one difference between evaporation and boiling.[1]
3. (b)(i)When a refrigerator is switched on, cooling coils placed at the top of the space inside the refrigerator become cold. This causes a convection current which cools the air inside the refrigerator. The refrigerator is shown in Fig. 4.1. [Figure 4.1] Explain how the cooling coils cause a convection current in the air inside the refrigerator.[2]
4. (b)(ii)The food in the refrigerator is initially at a temperature of 20.0°C. The food has a mass of 3.6 kg and a specific heat capacity of 3000 J/(kg°C). Calculate the final temperature of the food after 160000 J of thermal energy is removed from it. final temperature = .................................................... °C[2]

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