Three vessel of equal capacity have gases at the same temperature and pressure. The first vessel contains neon (monoatomic), the second contains chlorine (diatomic), and the third contains uranium hexafluoride (polyatomic). Do the vessels contains equal number of respectice molecules ? Is the root mean square speed of molecules the same in the three cases ? If not, which case is `v_(rms)` the largest?

Explanation

Three vessels at the same pressure and temperature have same volume and contain equal number of molecules.
`V_(rms)=sqrt((3RT)/(m))`, `V_(rms) prop (1)/(sqrt(m))`
rms speed will not same, neon has smallest mass therefore rms speed will be largest for neon.