Melting, boiling and evaporation — return questions

1. state / describe / explain

Answer from memory. (a) State the melting point and the boiling point of pure water at standard atmospheric pressure. (b) Ice at 0 °C is heated until it has all melted. Describe what happens to its temperature, and explain where the energy goes. (c) Describe condensation in terms of particles. (d) Describe solidification in terms of particles. (e) Ice at −20 °C is heated steadily until the water boils. Describe the shape of its heating curve, and say what is happening along each level part.

(a) Melting point and boiling point

(b) Melting ice

(c) Condensation

(d) Solidification

(e) The heating curve

2. describe / state / explain

Answer from memory. A swimmer climbs out of the sea on a warm, windy beach and soon feels cold, although the air is warm. (a) Describe evaporation in terms of particles. (b) State what evaporation does to the temperature of the water that stays on her skin, and explain why. (c) Explain how the evaporating water cools her skin. (d) Explain why she feels colder in the wind than in a sheltered spot. (e) Describe two differences between evaporation and boiling. (f) Later she wants her beach towel to dry quickly. She can spread it out flat on the hot sand in the sun, or leave it rolled up in her bag. Explain which way it dries faster, in terms of temperature and surface area.

(a) Evaporation

(b) The water that stays

(c) How the skin cools

(d) Why the wind matters

(e) Evaporation and boiling

(f) Drying her towel