A sealed rigid flask of gas is cooled while remaining a gas. A student claims that the lower pressure means each particle has become lighter. Which pair of statements correctly evaluates this claim?
Particle mass is unchanged; lower mean speed reduces collision rate and the mean force on the wall.
Particle mass decreases; lower mean speed reduces collision rate and the mean force on the wall.
Particle mass is unchanged; lower mean speed increases collision rate and the mean force on the wall.
Particle mass increases; lower mean speed increases collision rate and the mean force on the wall.
108 exam-style questions on Edexcel GCSE Physics 14.3 Gas pressure and temperature, covering 14.3.1 Gas pressure and particle motion, 14.3.2 Temperature and pressure at constant volume, 14.3.3 Absolute zero and the kelvin scale, 14.3.4 Compressing and expanding gases, 14.3.5 Volume and pressure at constant temperature, and 14.3.6 Doing work on a gas. Each one has a worked solution and a mark scheme showing where the marks go.