Answer: RMS speed.
- A Most probable speed
- B Average speed
- C RMS speed
- D All are equal
Correct answer: C. RMS speed
Explanation: The order is v<sub>p</sub> < v<sub>avg</sub> < v<sub>rms</sub>; the root mean square speed is always the highest of the three.
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.