Hydrogen Bonding water and ammonia

3D Model

Hydrogen bonding is an intermolecular force since it is between molecules. The hydrogen is between a electronegative atom in the same molecule and a electronegative atom in a different molecule. The electronegative atom in the same molecule than the hydrogen, gives the hydrogen a slightly positive charge (delta positive). The slightly positive hydrogen get attracted to the electronegative atom in the other molecule leading to hydrogen bonding.