Determine the Group of the Periodic Table Elements

Trick to find Periodic Table Elements Group number

Group Number = Number of valence electrons

We must understand a few guidelines to determine the group:

1. The group number is equal to the number of valence electrons if the element is in the s block.
   Example: Mg(12) – 2,8,2
   Group = no. of valence electrons = 2
   2. If the element is in the p block, the following formula can be used to obtain the group number:

(number of valence electrons + 10).for groups.
Example: S(16) – 2,8,6
Group = no. of valence electrons+ 10 = 6+ 10 = 16

3. The following formula can be used to find the number of the group if the element is in the d block:

number of electrons in(n−1)d subshell + (number of electrons in (n)s subshell).
Example: Fe(26): [Ar]3d64s2
Group = number of electrons in(n−1)d subshell + (number of electrons in (n)s subshell) = 6+2 = 8
4. The group number is always 3, if the element is in the f block.

Example: Cerium (58) belongs to 3rd group

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