Hydrogen bonding is the strongest form of secondary bonding and is formed from the polar nature of molecules containing hydrogen.
The hydrogen side of the molecule is more positive than the atom it is bonded to, allowing an attraction to form with the negative end of another molecule.
In hydrogen bonding, the hydrogen is attached directly to an element which is electronegative. This causes the hydrogen to acquire a significant positive charge.
The melting and boiling points of materials containing hydrogen bonding, are abnormally high, for their atomic weights, due to hydrogen bonding.
