Chapter 6, Problem 83A

Interpretation Introduction

Interpretation:

The reason due to which there are no p-block elements in the first period needs to be explained.

Concept introduction:

The first period of the periodic table contains only two elements hydrogen and helium. They do not obey the octet rule. Due to the chemically inactive behavior, helium is taken as the group 18 element.

Answer to Problem 83A

The orbitals of first period elements occupied by only two valence electrons it cannot accept more than two electrons. But p block contains more than two electrons. So, the first period does not contain p block elements.

Explanation of Solution

Only s-orbital occupies principal energy level 1. This orbital is occupied by two electrons and it cannot accept more than two electrons. The p orbitals contain a maximum of two electrons, but there are three p orbitals. Hence, the maximum electron holding capacity is six. That means p block contains more than two electrons. Hence, the first period does not contain p block elements.