1. p-Block elements: Elements belonging to groups 13 to 18 of the periodic table are called p-block elements.
2. General electronic configuration of p-block elements: The p- block elements are characterized by the ns 2 np 1-6 valence shell
electronic configuration.
3. Representative elements: Elements belonging to the s and p- blocks in the periodic table are called the representative elements or main group elements.
4. Inert pair effect: The tendency of ns 2 electron pair to participate in bond formation decreases with the increase in atomic size. Within a group the higher oxidation state becomes less stable with respect to the lower oxidation state as the atomic number increases. This trend is called‘ inert pair effect’. In other words, the energy required to unpair the electrons is more than energy released in the formation of two additional bonds.
5. Nitrogen family: The elements of group 15 – nitrogen( N), phosphorus( P), arsenic( As), antimony( Sb) and bismuth( Bi) belong to configuration is ns 2 np 3.
6. Oxygen family: Group 16 of periodic table consists of five elements – oxygen( O), sulphur( S), selenium( Se), tellurium( Te) and polonium( Po). Their general electronic configuration is ns 2 np 4.
7. The halogen family: Group 17 elements, fluorine( F), chlorine( Cl), bromine( Br), iodine( I) and astatine( At), belong to halogen family. Their general electronic configuration is ns 2 np 5.
8. Group 18 elements: Helium( He), neon( Ne), argon( Ar), krypton( Kr), xenon( Xe), and radon( Rn) are Group 18 elements. They are also called noble gases. Their general electronic configuration is ns 2 np 6 except helium which has electronic configuration 1s 2. They are called noble gases because they show very low chemical reactivity.