Question

Calculate the pressures, P, in atmospheres at which the mean free path, l, of a hydrogen molecule will be 5.00 μm, 5.00 mm, and 5.00 m at 20.0 °C. The diameter of a H2 molecule is 270 pm.

I= 5.00μm 5.00mm 5.00m
P= ? atm ? atm ? atm