IONIC BONDING: this occurs between metal and nonmetal atoms. It occurs as a result of electron transfer from one atom to another.
Example: NaCl is an ionic compound (between a metal, Na, and a nonmetal, Cl)
POLAR COVALENT: 2 atoms share bonded pairs of electrons sort of unequally. Electrons in a polar covalent bond are more attracted to one atom than the other atom. This type of bonding occurs between nonmetals.
Example: HF has polar covalent bonds
NONPOLAR COVALENT: occurs between nonmetals atoms. this type of bonding occurs between atoms with almost the same electronegativity.
Example: N2