= Solution
The <rotational state populations> start at $N_0/N_0=1$. Their $2J+1$ <statistical weight> factor initially favors higher $J$, while the <Boltzmann factor> eventually suppresses them, producing one maximum followed by a tail tending to zero. The physically allowed values occur at integer $J$; a continuous curve only guides the eye.
\Image[/past-exam-of-the-chemistry-a-course-of-the-university-of-cambridge/2021/paper-1-carbon-monosulfide-populations.png]
{title=Original <linear rigid rotor> populations for <carbon monosulfide> at $300\ \mathrm K$ and $8.7\ \mathrm K$}
Back to article page
