Use Hund's rule to derive the electronic configuration of Ce 3+ ion and calculate its magnetic moment on the basis of a spin only formula.

Question

Philoid · Accepted Answer

Theatomic number of Cerium (Ce) is Z = 58.

The electronic configuration of ₅₈Ce= [Xe]⁵⁴ 4f¹ 5d¹ 6s²

And, the electronic configuration of Ce³⁺= [Xe]⁵⁴ 4f¹ , i.e., there is only one unpaired electron, i.e., n = 1.

Now, the magnetic moment on the basis of spin only formula is given as:

μ = √n(n+2) BM

⇒ μ = √1(1+2)

⇒ μ = √3 BM

⇒ μ = 1.73 BM

Note: Bohr magneton or BM is a unit for expressing the magnetic moment of an electron caused by its orbital or spin angular momentum.