Question

What is the general electronic configuration of actinide series? Select the proper choice from the given choices.
(A) [Xe] 4f⁰⁻¹⁴ 5d⁰⁻¹ 6s²
(B) [Xe] 4f⁰⁻¹⁴ 5d⁰⁻¹⁰ 6s²
(C) [Rn] 5f⁰⁻¹⁴ 5d⁰⁻² 6s²
(D) [Rn] 5f⁰⁻¹⁴ 6d⁰⁻² 7s²

Answer 1

(D) [Rn] 5f⁰⁻¹⁴ 6d⁰⁻² 7s²
The configuration is expected to be [Rn] 5f⁰⁻¹⁴ 6d⁰ 7s², because 5f-orbital is progressively filled. But due to stabilty on the ground of maximum pairing and exchange energy the configuration gets deviated slightly. Therefore, the configuration remains [Rn] 5f⁰⁻¹⁴ 6d⁰⁻² 7s²