Question

The number of 4f electrons in the ground state electronic configuration of $G{d}^{2+}$ is ______________.
[Atomic number of Gd $=64$]

JEE MAINS 2021

Answer 1

Atomic number of Gd is $64$

Electronic configuration of Gd is $\left[Xe\right]4f^{7}5d^{1}6s^2$

$G{d}^{2+}=\left[Xe\right]4f^{7}5d^1$