JEE Main202126 Aug 2021Morning ShiftChemistryd and f Block ElementsActual
The number of 4 f electrons in the ground state electronic configuration of Gd 2 + is [Atomic number of Gd = 64 ]
Correct answer
7
Step-by-step solution
Electronic configuration of Gd = [ Xe ] 4 f 7 5   d 1 6   s 2 Due to more stable exactly half-filled 4 f 7 shell, electron filling occur in a little higher energy 5 d - orbital So configuration of Gd 2 + = [ Xe ] 4 f 7 5 d 1