Chapter 5, Problem 50E

Interpretation Introduction

Interpretation:

The open spaces in the table are to be filled.

Concept introduction:

The elements in a modern periodic table are arranged in an increasing order of their atomic number. The horizontal rows are known as periods, and vertical columns are known as groups. There are $7$ periods and $18$ groups in a modern periodic table. They are categorized into groups based on the type of energy sublevel that the last valence electron of the element enters.