Valence and the Rule of Eight

Abstract

F. LONDON, in an interesting article (Zeit. f. Physik, 46, 455; 1928), attempts to account for the difference in valence behaviour between nitrogen, oxygen, and fluorine on one hand, and phosphorus, sulphur, and chlorine on the other, in terms of absolute quantum restrictions. The chemist has been inclined to account for the limited valence of nitrogen, oxygen, and fluorine on the grounds of energy relations; that is, many compounds do not occur because they are ‘unstable.’ Such an explanation is admittedly unsatisfactory.