Answer: The same number of molecules (Avogadro hypothesis).
- A The same average molecular speed
- B The same number of molecules (Avogadro hypothesis)
- C The same total kinetic energy regardless of moles
- D The same mass
Correct answer: B. The same number of molecules (Avogadro hypothesis)
Explanation: Equal volumes of any ideal gas at the same temperature and pressure contain the same number of molecules, consistent with Avogadros hypothesis and the ideal gas law.
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.