> Definition of solids

Solids are collection of molecules with strong intermolecular force, overcoming this force causes a phase transition.

> charges

Showcase of vander wall’s force of attraction.

> wall

Opening the wall, it forms molecule of H2, but as of now it’s single Hydrogen atom.

> new object

Hydrogen Molecule with a shared e- between them.

> Total interactions,

Since there are 5 electrons and 4 protons, interaction is a combination of these,

n is for the electrons, N is for the protons.

> “d”

Smallest possible d so, the total energy term is more negative.