Chapter EH, Problem 21R

Solution

Interpretation: To compare the electronic configuration of the main transition elements and inner transition elements.

Concept Introduction: The elements in which the last electron enters in d-subshell, are named transition elements. They are placed in between s-block and p-block elements.

The electronic configuration of the inner transition element is ${\text{4f}}^{\text{(1-14)}}{\text{5d}}^{\text{0}}{\text{6s}}^{\text{2}}$ .

The electronic configuration of the main transition element is ${\text{(n-1)d}}^{\text{1-10}}{\text{(n-1)s}}^{\text{1-2}}$

The elements whose last electrons enter the d-subshell are named d-block elements hence, they will be kept in the d-block of the periodic table whereas the type of elements whose last electrons enter the f-subshell is named inner transition elements. They will be kept in the f-block in the periodic table.

• The electronic configuration of the inner transition element is ${\text{4f}}^{\text{(1-14)}}{\text{5d}}^{\text{0}}{\text{6s}}^{\text{2}}$ .
• The electronic configuration of the main transition element is ${\text{(n-1)d}}^{\text{1-10}}{\text{(n-1)s}}^{\text{1-2}}$