Question

The parameter that remains the same for molecules of all gases at a given temperature is :

• A. kinetic energy
• B. momentum
• C. mass
• D. speed

Answer 1

Answer: (A)

kinetic energy

Answer 2

The kinetic energy of gas molecules at a given temperature is given by:

$KE = \frac{f}{2}kT$

where $f$ is the degrees of freedom and $kT$ is the thermal energy term.

This is a conceptual fact based on the equipartition theorem, which states that all gases at a given temperature have the same average kinetic energy per molecule.