When sweat evaporates from a person's skin, it produces a cooling effect. Which statement correctly explains why this evaporation cools the remaining liquid on the skin?
The least energetic molecules escape, leaving behind molecules with a higher average kinetic energy, which decreases the temperature.
The least energetic molecules escape, leaving behind molecules with a lower average kinetic energy, which increases the temperature.
The most energetic molecules escape, leaving behind molecules with a lower average kinetic energy, which decreases the temperature.
The most energetic molecules escape, leaving behind molecules with a higher average kinetic energy, which increases the temperature.
528 exam-style questions on CIE IGCSE Physics 2.2 Thermal properties and temperature, covering 2.2.1 Thermal expansion of solids, liquids and gases, 2.2.2a Internal energy and temperature, 2.2.2b Specific heat capacity, 2.2.3a Melting, boiling, condensation and solidification, 2.2.3b Evaporation, and 2.2.3c Cooling by evaporation. Each one has a worked solution and a mark scheme showing where the marks go.