On the basis of filling of valence electrons in the orbitals, the elements have been divided into four block that are explained below :
s-block elements : Those elements whose valence electron enter in s-orbital are called s-block elements. The elements of group-I and II (A and IIA) of the periodic table belongs to this block. The general valence shell electronic configuration of these elements is ns1 for the alkali metals and ns2 for the alkaline earth metal.
p-block elements : Those elements whose valence electron enter in p-orbital are called p-block elements.
The general valence shell electronic configuration of these elements is ns2 np1-6 .
The elements of group-13 to 18 (III A to VIII A) of the periodic table are p-block elements.
d-block elements : The elements whose valence electron enter in d-orbital is called d-block elements. Except zinc, cadmium and mercury, these elements are called transition elements
The general valence shell electronic configuration of d -block elements are (n-1)d1-10 ns1-2
f-block elements : The f-block elements of the periodic table consists of two series lanthanoids and actinoids.
The electronic configuration of lanthanoids is 6s25d0-24f1-14 but the electronic configuration of actinoids are irregular.
The f-block elements are also called inner-transition elements.
Some Important Facts of the Elements
