When two atoms,and both of which tend to gain extra electrons, may combined with each other by sharing one or more pairs of electrons. For example, an atom of Chlorine and an atom of Fluorine, both of these element have seven electrons in its outer shell, they unite by sharing two of these fourteen electrons in its outer shell. As a result of sharing a pair of electrons, each atom has a complete shell of eight electrons. The word "complete" is meant an outside shell similar to a noble gas. The strong force that binds the two elements of chlorine atom to the fluorine atom is the attraction of each electrons that are held jointly. A shared pair of electrons is called a "covalent bond" they may also be called as covalent compounds.
