covlalent+bonding

Covalent compounds contain covalent bonds. A covalent bond is defined as the chemical bond formed between two elements in a compound where an electron pair is shared between the atoms.

These bonds occur primarily between nonmetallic elements.

There are two classifications of covalent bonds:
 * nonpolar covalent, occurring between two atoms of the same element or two atoms having the same electronegativities;
 * polar covalent, occurring between two atoms having differing electronegativity values.
 * any difference in electronegativity values between zero and 1.7 is considered a covalent bond.

You can predict the number of bonding sites a nonmetallic element will have by subtracting its group number from eight (the octet rule).