Medical Physiology/Basic Biochemistry/Basic Chemistry

Chemical bonds
there are generally two types of bonds:-

1)intra{within}molecular forces

2)inter{between}molecular forces the intramolecular forces, are forces of attraction between atoms in a molecule i.e. the force of attraction between atoms that forms molecules e.g. ionic and covalent bonding.

the intermolecular forces, are ones between molecules that forms substances e.g. van deer waals, dipole-dipole, hydrogen bonds

Hydrogen Bonds
when H is bonded to more electronegative elements (especifically- F2,O2,N2),H carries a partial positive charge 'due to the electronegativity difference' which enable it to bond with the more electronegative element in adjacent molecule, thus H acts as a bridge between the more electronegative atoms in adjacent molecule. H bond can be viewed as special type of permanent dipole-dipole force.