Compare the number of collisions per unit time against a wall with given surface $A$ of a container containing oxygen or hydrogen at the same temperature and pressure.
$\frac{collisions_{H_2}}{collisions_{O_2}}=$
$ \frac{A\frac{P\sqrt{N_A}}{\sqrt{2\pi \cdot 0,002\cdot k\cdot T}}}{A\frac{P\sqrt{N_A}}{\sqrt{2\pi \cdot 0,032\cdot k\cdot T}}}=$
$\sqrt{\frac{0,032}{0,02}}=4$
There are 4 times more hydrogen collisions against the wall!
