The translational kinetic energy of an ideal gas depends only on its

Two gases $A$ and $B$ are released from the two ends of a tunnel of length $100 \ m$. $A$ travels $40 \ m$ before meeting the gas $B$ in the tunnel. If the molecular weight of $B$ is $18$, what is the molecular weight of $A$ (in $.5$)?

$A$ $He$ atom is twice as heavy as a hydrogen molecule. At $25\,^oC$,the kinetic energy of a $He$ atom is:

What is the temperature at which the kinetic energy of $0.3 \ mol$ of helium is equal to the kinetic energy of $0.4 \ mol$ of argon at $400 \ K$ (in $K$)?

At the same temperature and pressure,which of the following gases has the highest kinetic energy $(K.E.)$ per mole?

What is an elastic molecular collision?