Explain about the classification of elements based on electronic configuration.

Explanation

(i) The distribution of electrons into orbitals, s, p, d and f of an atom is called its electronic configuration. The electronic configuration of an atom is characterized by a set of four quantum numbers, n, l, m and s. Of these the principal quantum number (n) defines the main energy level known as shells.
(ii) The position of an element in the periodic table is related to the configuration of that element and thus reflects the quantum numbers of the last orbital filled.
(iii) The electronic configuration of elements in the periodic table can be studied along the periods and groups separately for the best classification of elements.
(iv) Elements placed in a horizontal row of a periodic table is called a period. There are seven periods.
(v) A vertical column of the periodic table is called a group. A group consists of a series of elements having similar configuration of the outermost shell. There are 18 groups in periodic table.