A porous clay pot filled with water is used to keep its contents cool in a hot, dry climate. Water slowly seeps through the clay and evaporates from the outer surface.
Which molecules escape from the water during evaporation, and what happens to the average kinetic energy of the water molecules that remain?
Escaping molecules: those with lower kinetic energy; Average kinetic energy of remaining molecules: decreases
Escaping molecules: those with lower kinetic energy; Average kinetic energy of remaining molecules: increases
Escaping molecules: those with higher kinetic energy; Average kinetic energy of remaining molecules: decreases
Escaping molecules: those with higher kinetic energy; Average kinetic energy of remaining molecules: increases
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.