Question

what forces are involved in hydrogen bonding?

Answer 1

you have london forces, dipole-dipole, and hydrogen bonding.

Answer 2

Hydrogen bonding is a weak electro-magnetic bond, where the slightly positive hydrogen nucleus is drawn to the slightly negative electron shell of a nearby atom/molecule. It is the principle reason why water is generally water and not steam. It also explains why water is such a good solvent. Hydrogen bonds occur in the neighborhood of 240 picometers, where the strong bonds, ionic, and covalent, occur at about 120 picometers.