Question

The number of 4f electrons in the ground state electronic configuration of Gd²⁺ is ........[Atomic number of Gd = 64]

Answer 1

Answer is 7

The electronic configuration of 

₆₄Gd : [Xe] 4f⁷ 5d¹ 6s² 

So the electronic configuration of 

₆₄Gd²⁺ : [Xe] 4f⁷ 5d¹ 6s⁰ 

i.e. the number of 4f electrons in the ground state electronic configuration of Gd²⁺ is 7.