Question

can we say the elemental state of all the non-metals are the examples of non-polar molecular solids?

Answer 1

Non-polar Molecular solids possess atoms of noble gases like He, Ar and non-polar molecules like H_​​2, Cl₂ , I₂. There is weak vander waal forces of attraction between the molecules. Solid halogens, O₂ , N₂ are non-polar molecular solid.
You can not say that the elemental state of all non-metals are eg. of non-polar molecular solid because carbon (non-metal) exist as its allotropes like graphite, diamond. Graphite and diamond are eg. of covalent or network solid not non-polar molecular solid.