Question

The Lanthanoid series is the same as the Actinoid series.

(a) True

(b) False

This question was posed to me in an internship interview.

I need to ask this question from Electronic Configurations of Elements and the Periodic Table in section Classification of Elements and Periodicity in Properties of Chemistry – Class 11

Answer 1

Right answer is (b) False

The explanation is: Both the Lanthanoid series and the Actinoid series make up Inner transition elements, but they are not the same. The 4f elements are lanthanoids (Z = 57 to Z = 71) and 5f are actinides (Z = 89 to Z =  113).