Question

# Explain how the elements are classified into s, p, d and f-block elements in the periodic table and give the advantage of this type of classification.

The elements in which the valence shell electron enters the s-orbital are called s-block elements. For example let us take sodium. The electronic configuration of sodium is $1{s^2}2{s^2}2{p^6}3{s^1}$. From the electronic configuration we can conclude that the last electron enters the s-subshell. The elements in which the valence shell electron enters the p-orbital are called p-block elements. For example the electronic configuration of carbon is $1{s^2}2{s^2}2{p^2}$, in this the last electron enters the p-subshell.Similarly the elements in which the valence shell electron enters the d and f-orbitals then they are called as d and f-block elements respectively.