The right side of the periodic table having group number 13, 14, 15, 16, 17 and 18 are known as p – block elements. These elements have 3, 4, 5, 6, 7 and 8 electrons in their outer most shell, respectively. The last electron of these groups’ elements

occupies the position in p – sub shell that is why these elements are called as p – block elements. Their general electronic configuration is ns2np1-6.

Some important properties of p-block

(1) Electron affinity

Electron affinity increases from left to right along the period amongst the p – block elements and it decreases from top to bottom. But group 15 is having exceptionally low values of electron affinity and is due to extra stability of exactly half filled orbitals in their valence shell. Similarly, elements of group 18 (noble gases) have zero affinities due to presence of complete octet which provides them stability.

(2) Metallic Character

The metallic character is governed by

(i) Size of atoms and

(ii) Ionization energy.

The elements having bigger size and low ionization energy has a greater metallic character. After combining both the above mentioned factors we observe that the elements with above two properties are located in left corner of p – block and strong non – metallic elements are located at right corner and a diagonal strip of elements separates thus two, having in between properties are called as metalloids.