(a)[2]
An ideal gas is taken to be made up of atoms or molecules that behave like hard, identical spheres, are in continual motion, and undergo elastic collisions. State two further assumptions of the kinetic theory of gases.
(b(i))[1]
Helium-4 ($^{4}_{2}\text{He}$) may be treated as an ideal gas. Show that the mass of one helium-4 atom is $6.6 \times 10^{-24}\,\text{g}$.
(b(ii))[3]
The mean kinetic energy $E_{K}$ of an atom of an ideal gas is given by $E_{K} = \frac{3}{2}kT$. Calculate the root-mean-square (r.m.s.) speed of a helium-4 atom at a temperature of $27^{\circ}\text{C}$.