A-LevelPhysicsIdeal gases9702/12 · Oct/Nov 2014 · Q181 Mark

Which statement about molecules in a gas is correct?

AIn Brownian motion experiments, the molecules can be seen moving randomly in all directions.

BThe pressure exerted by a gas is caused by molecules bouncing against each other and changing kinetic energy.

CThe pressure exerted by a gas is caused by molecules rebounding from the walls of a container and changing momentum.

DWhen the average speed of the molecules in a closed container increases, the density must also increase.

✓ Correct answer

C: The pressure exerted by a gas is caused by molecules rebounding from the walls of a container and changing momentum.

Oracle Prep sorts past-paper questions by topic, so you can drill Ideal gases and see which topics are most likely to come up next.

Topic: Ideal gases, A-Level Physics (syllabus 9702). Multiple choice, 1 mark.
Source: A-Level Physics, Oct/Nov 2014 Paper 1 Variant 2, question 18.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content