During a marathon, a runner's body is cooled as sweat evaporates from their skin.
Which of the following describes the molecules that escape from the liquid sweat during evaporation, and the change in the average speed of the remaining sweat molecules?
The more energetic molecules escape, and the average speed of the remaining molecules decreases.
The more energetic molecules escape, and the average speed of the remaining molecules increases.
The less energetic molecules escape, and the average speed of the remaining molecules decreases.
The less energetic molecules escape, and the average speed of the remaining molecules increases.
313 exam-style questions on CIE IGCSE Physics 2.2.3a Melting, boiling, condensation and solidification. Each one has a worked solution and a mark scheme showing where the marks go.