Question

The elements whose atoms have three outermost shells incomplete are called A. s-block elements B. p-block elements C. f-block elements D. d-block elements

Answer 1

The explanation for the correct option:

Option(C) f-block elements

• ​The outer electronic configuration of f-block elements is $(n-2)f^{1-14}(n-1)d^{0-1}n{s}^2$
• Since this configuration shows that its $n^{th},{(n-1)}^{th}and{(n-2)}^{th}$ all are incomplete
• Hence, The elements whose atoms have three outermost shells incomplete are called f-block elements

The explanation for the incorrect option:

(A) s- block elements, the outer electronic configuration is $n{s}^{0-2}$, hence only one orbital would be incomplete

(B) p-block elements, the outer electronic configuration is $n{s}^{2}n{p}^{1-6}$, hence only one orbital would be incomplete, that is p only

(D) d-block elements, the outer electronic configuration is $n{s}^{2}n{d}^{1-10}$ hence only one orbital would be incomplete, that is d only.

hence, Option(C) f-block elements is the elements whose atoms have three outermost shells incomplete