Chapter 9, Problem 72E

Interpretation Introduction

Interpretation: The number of elements in $4^{\text{th}}$ period of the periodic table and that belonging to $f$-block is to be given.

Concept Introduction:

Periodic table is the arrangement of elements in rows and columns according to their atomic numbers.

The rows in the periodic table are known as periods and the columns are known as groups.

$f-$ block comprises of inner transition metals (lanthanides and actinides).