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

Number of electrons present in 4f orbital of Ho³⁺ ion is ____________. (Given Atomic No. of Ho = 67)

Number of electrons that Vanadium (Z = 23) has in p-orbitals is equal to _____________

In the ground state of atomic Fe(Z = 26), the spin-only magnetic moment is ____________ $$\times$$ 10^$$-$$1 BM. (Round off to the Nearest Integer). [Given : $$\sqrt 3 $$ = 1.73, $$\sqrt 2 $$ = 1.41 ]