A student rubs a small amount of liquid alcohol onto their skin. As the alcohol evaporates, the skin feels cold.
Which statement correctly explains this observation in terms of molecular kinetic energy and temperature?
The more energetic molecules escape from the liquid, decreasing the average kinetic energy of the remaining molecules and lowering the temperature.
The more energetic molecules escape from the liquid, increasing the average kinetic energy of the remaining molecules and raising the temperature.
The less energetic molecules escape from the liquid, decreasing the average kinetic energy of the remaining molecules and lowering the temperature.
The less energetic molecules escape from the liquid, increasing the average kinetic energy of the remaining molecules and raising 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.