What does hydrogen interact with?

Hydrogen bonds can exist between atoms in different molecules or in parts of the same molecule. One atom of a pair (donor), usually a fluorine, nitrogen or oxygen atom, is covalently bonded to a hydrogen atom (—FH, —NH, or —OH), the electrons of which it shares unevenly; its high electron affinity gives hydrogen a slight positive charge. The other atom in the pair, also typically F, N or O, has an unseparated electron pair, which gives it a slight negative charge. Mainly due to electrostatic attraction, the donor atom effectively separates its hydrogen with the acceptor atom, forming a bond.