Why boiling point is more when vanderwall force if more?

It is the intermolecular forces acting between the molecules that cause attractions between them making them liquids or solids. The strength of Van der Waals forces depends primarily on the number of electrons in total in the molecule, so larger molecules will have higher boiling points.

Explanation:

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements