The temperature of an ideal gas is reduced from $927^\circ C$ to $27^\circ C$. The $r.m.s.$ velocity of the molecules becomes

Two containers $A$ and $B$ contain an ideal gas at the same temperature. If the masses of the molecules are $m_A$ and $m_B$ respectively,what is the relationship between their momenta $p_A$ and $p_B$?

In a closed container,the same number of hydrogen $(H_2)$ and carbon dioxide $(CO_2)$ molecules are kept. If a small hole is made in the container,which gas will effuse out faster?

The $r.m.s.$ speed of the molecules of a gas at a pressure $10^5 \ Pa$ and temperature $0^\circ C$ is $0.5 \ km \ sec^{-1}.$ If the pressure is kept constant but temperature is raised to $819^\circ C,$ the velocity will become ........ $km \ sec^{-1}.$

The $r.m.s.$ velocity of nitrogen molecules at $NTP$ is ...... $m/s$.

Light gases like $H_2$ and $He$ are found in negligible amounts in the atmosphere. Why?