Answer: mean square speed.
- A mean square speed
- B the net charge
- C the apparent colour
- D the mass alone
Correct answer: A. mean square speed
Explanation: Pressure depends on the mean square speed of the molecules.
Not all gas molecules move at the same speed - the Maxwell-Boltzmann distribution shows the spread, with the most probable speed vp slightly less than the average vavg, which is slightly less than the root-mean-square speed vrms used in the pressure formula.
Concept context
Kinetic theory of gases connects molecular motion to pressure and temperature, explaining gas laws, specific heats, and molecular speeds.