The atomicity of a noble gas is

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Amongst $\mathrm{He}, \mathrm{Ne}, \mathrm{Ar}$ and $\mathrm{Kr}$; $1 \mathrm{g}$ of activated charcoal adsorbs more of $\mathrm{Kr}$.

Reason R: The critical volume ${\mathrm{V}}_{\mathrm{c}} ({\mathrm{cm}}^3 {\mathrm{mol}}^{–1})$ and critical pressure ${\mathrm{P}}_{\mathrm{c}}$ (atm) is highest for Krypton but the compressibility factor at critical point ${\mathrm{Z}}_{\mathrm{c}}$ is lowest for Krypton.

In the light of the above statements, choose the correct answer from the options given below.

Account for the following:

Boiling point of noble gases increases from $\mathrm{He}$ to $\mathrm{Rn}$.

Noble gases are named because of their inertness towards reactivity. Identify an incorrect statement about them.

Answer the following :

Noble gases have very low boiling points. Why?