Question

I=$He$ II= $Ne$ III=$Ar$ IV=$Kr$
Decreasing order of melting point of compound I-IV follows:

• A. IV > III > II > I
• B. I > II > III > IV
• C. II > III > IV > I
• D. II > IV > III > I

Answer 1

The correct option is A IV > III > II > I

Option $\left(A\right)$ is correct.

Melting point increases down the group for noble gases from $He$ to $Rn$.This is due to increase in atomic size, an atomic radius which leads to increase in interatomic forces thus results in an increased melting point.

Decreasing order of melting point of noble gases is as follows:

$Rn>Xe>Kr>Ar>Ne>He$