The stronger the vanderwall force the higher the boiling point.
To melt or boil a simple molecular substance we must overcome the intermolecular force.
For example if not because of the intermolecular force that holds molecules together everything in the universe will have been in gaseous form, but because of the intermolecular force that acts between them, lead to the formation of liquid and solid phase substance.
The intermolecular force between some of the molecules are stronger than the other as a result of the ability of this molecule to attract the electron to itself as such the stronger the intermolecular force the higher the energy required to convert liquid and solid to gaseous phases.
The energy required to convert liquid to gas is higher than the energy required to convert solid to gas and hence this lead to higher boiling point of solid followed by liquid.
So since the strength of van der waal force solely depends on the sum of the number of electron present in the atomic molecule, I.e the higher the number of electron present in the atomic molecule the stronger the van der waal force of that atom molecules and the higher the energy required to melt that atomic molecule. In reverse the lower the number of electron present in the atomic molecule the lesser the energy required to melt the atom of the molecule. So since noble gas atom has a weak van der waal force that’s simply mean noble gas required less energy to melt it molecule, hence noble gas have lower boiling and melting point. Helium is the element with lowest melting point among all atom in the periodic table.Omokoshaban.com News Updates, and Education Mobile App.