Question

For d block: Group Number = Number of e − in (n−1)d subshell + number of e − in ns subshell explain with example​

Answer 1

Answer:

For d block: Group Number = Number of e − in (n−1)d subshell + number of e − in ns subshell explain with example​

Explanation:

Prediction of Period ⟶ In the electronic configuration of an atom, the principal quantum number (n) of the valence electrons represents the period of an element.

Prediction of Block ⟶ The orbital out of s,p,d and f which receives the last electron represents the block of an element

Prediction of Group ⟶ The group prediction occurs with the help of block as:-

(1) For s block: Group Number = Number of valence e  

−

 

(2) For d block: Group Number = Number of e  

−

 in (n−1)d subshell + number of e  

−

 in ns subshell

(3) For p block: Group Number = Number of valence e  

−

+10

(4) For f-block: Group Number = 3 (always)

For example for chlorine with Z=17

Electronic configuration = 1s  

2

2s  

2

2p  

6

3s  

2

3p  

5

 

Since the last e  

−

 enters in p - subshell:

(i) ∴ Block will be  

′

p  

′

 

(ii) For group we have element in p-block

∴ Group number = 10+ Valence e  

−

 in s subshell + Valence e  

−

 in p subshell

Group Number = 10+2+5=17

(iii) For period

The quantum number of valence e  

−

=3

∴ Period number = 3