Question

The valence of representative elements is either equal to the number of the valence electrons or eight minus this number. What is the basis of this rule?

Answer 1

The electrons in the outermost orbit of an atom are called valence electrons. These electrons are used in bonding; hence determine the valence of the element. In the representative elements, the outermost orbit contains electrons numbering 1 to 7 (i.e., ns¹ to ns² ns⁵) Thus, to achieve a complete octet, it should either lose all electrons in its outer most orbit or accept (8 no. of valence electrons) electrons from some other atoms. Hence, the elements in this class show a valence given by the number of the valence electrons or eight minus the number of electrons it accepts from other atoms.