DESCRIPTION OF GROUPS IN THE LONG FORM OF PERIODIC TABLE

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  • The vertical columns starting from top to bottom are called groups. 
  • There are 18 groups in the periodic table and the groups are denoted by IA to VIIA, IB to VIIB, VIII (three columns), Zero group. 
According to latest convention the groups are number as 1 to 18.

CHARACTERISTICS OF GROUPS

(1) Valency :-

Valency of all the elements in a group are same. 

Ex:- All the elements of group 1 , i.e. Li, Na, k, Rb, Cs, Fr have the valency one. 

(2) Similar properties:-

All the elements of same group have similar properties as they have same valencies. 

Ex:-All elements of group 1 have low ionization energy. 

(3) Prediction of properties :-

The group number of an element helps to predict the property of that element, by knowing the property of one element and the properties of other elements in the same group can be predicted. 

(4) Gradation of properties :-

The elements of same group have gradually change in properties with increasing in atomic number when we move from top to bottom.  

Description of Groups

Group - 1/ IA (Alkali metals) 

  • Elements are H, Li, Na, K, Rb, Cs, Fr. 
  • General electronic configuration is nS1
Ex:- H -- 1S1

           Li -- 1S2    2S1

         Na -- 1S2   2S2   2p6   3S1

Group - 2/IIA (Alkali Earth metal) 

  • Elements are Be, Mg, Ca, Sr, Ba, Ra. 
  • General electronic configuration is nS2
Ex :- Be -- 1S2  2S2
      Mg -- 1S2  2S2  2p6  3S2

Group - 13/IIIA (Boron family) 

  • Elements are B, Al, Ga, In, Tl. 
  • General electronic configuration is nS2  np1
Ex:- B -- 1S2  2S2  2p1

     Al -- 1S2   2S2   2p6   3S2   3p1

Group - 14/IVA (Carbon family) 

  • Elements are C, Si, Ge, Sn, Pb. 
  • General electronic configuration is nS2  np2
Ex :- C -- 1S2   2S2   2p2 

        Si -- 1S2  2S2   2p6   3S2   3p2

Group - 15/VA (Nitrogen family) [Pincogen]

  • Elements are N, P, As, Sb, Bi. 
  • General electronic configuration is nS2  np3
Ex:- N -- 1S2  2S2  2p3

        P -- 1S2  2S2  2p6  3S2  3p3

Group - 16/VIA (Oxygen family) [Chalcogen]

  • Elements are O, S, Se, Te, Po. 
  • General electronic configuration is nS2  np4
Ex:- O -- 1S2   2S2   2p4

        S -- 1S2   2S2   2p6   3S2   3p4 

 Group - 17/VII (Halogen family) 

  • Elements are F, Cl, Br, I, At. 
  • General electronic configuration is nS2  np5
Ex:- F -- 1S2  2S2  2p5

       Cl -- 1S2  2S2  2p6  3S2  3p5

Group - 18/0 (Inert gas) [Noble gas]

  • Elements are He, Ne, Ar, Kr, Xe, Rn. 
  • General electronic configuration is nS2   np6 (except He). 
Ex :- Ne -- 1S2   2S2    2p6









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