Some of the nonmetals, the right side of the table, form compounds with each other. Since these elements have somewhat similar traits, they should tend to form covalent bonds. It is important to understand that chemical bonding is never totally ionic or totally covalent. Chemical bonds will have some traits of each type of bond. Many times bond type is expressed as a percentage of each type of bond.
All chemical reactions occur between electrons in the outer energy level of atoms.
The most stable atoms - their outer energy level is full . The Octet Rule - the maximum number of electrons in the outer energy level is 8. Atoms will form compounds to reach eight electrons in their outer energy level. Atoms with less than 4 electrons in their outer level tend to lose electrons to form compounds. Atoms with more than 4 electrons in their outer level tend to gain electrons to form compounds.