AP EAMCET202119 Aug 2021Evening ShiftChemistryd and f Block ElementsActual
The electron configuration of F e 3 + is (atomic number of F e = 26 )
Options
- A[ A r ] 3 d 5 4 s 1
- B[ A r ] 3 d 6 4 s 0
- C[ A r ] 3 d 5 4 s 0
- D[ A r ] 3 d 6 4 s 2
Correct answer
C. [ A r ] 3 d 5 4 s 0
Step-by-step solution
We know that atomic number of Fe is 26 and its a d - block element and it belongs to 4 th period and 8 th group also the general electronic configuration for d - block elements is ( n − 1 ) d 1 − 10 ns 1 − 2 where n is the period number. So, for the ferrous atom the configuration will be Fe   =   Ar 3 d 6 4 s 2 Now, at the 3 rd excited state the electronic configuration of ferrous ion will be Fe 3 +   =   Ar 3 d 5 4 s 0