In case of group 18 elements, explain the variation in melting and boi

1.	In case of group 18 elements, explain the variation in melting and boiling points.
Answer» Melting points and boiling points : Group 18 elements have very low melting points and boiling points. The melting points and boiling points increase down the group from He to Rn. As the size of the atoms increases on moving down the group, the magnitude of the van der Waals forces increase from He to Rn. Thus, the melting and boiling points increase from He to Rn. Helium has the lowest boiling point (4.2 K) of any known substance. The boiling points increase in the order He < Ne < Ar < Kr < Xe < Rn

In case of group 18 elements, explain the variation in melting and boiling points.

Answer»

Melting points and boiling points :

Group 18 elements have very low melting points and boiling points.
The melting points and boiling points increase down the group from He to Rn.
As the size of the atoms increases on moving down the group, the magnitude of the van der Waals forces increase from He to Rn.
Thus, the melting and boiling points increase from He to Rn. Helium has the lowest boiling point (4.2 K) of any known substance.
The boiling points increase in the order He < Ne < Ar < Kr < Xe < Rn