Ionic bonds occur between two atoms when the electronegative force between them is great. In an ionic bond, electrons from the atom with the smaller electronegativity are transferred to the atom with the larger electronegativity. As a result, one atom has a positive charge and the other has a negative charge. Opposite charges attract, causing the two atoms to remain together to form an electrically neutral ionic compound. Since atoms do not lose their electrons when they are isolated, conditions must favor the release of the electron(s) from the less electronegative element for the bond to form. In other words, energy is released when an ionic compound forms. Basically, three sources of energy are factors. One element must lose an electron, one element must gain an electron, and the coulombic attraction between the two compounds must be considered. If the coulombic attraction between the two species is great enough, an ionic bond will form. The potential energy between two atoms is found by the formula
