Question

Which noble gas has the lowest boiling point?

• A. $Kr$
• B. $He$
• C. $Ar$
• D. $Ne$
• E. $Xe$

Answer 1

The correct option is B $He$

All the given options of elements belong to same group $\left({18}^{th}\right)$. The boiling point (BP) of elements increases with increasing size due to increase in Vanderwaals forces. Thus the BP increases down the group. Hence least boiling point is of topmost element, i.e. $He$ (Helium) in this case.