Chapter 8, Problem 8.17P

Interpretation Introduction

Interpretation:

The role of the Aufbau principle, in connection with the periodic law in the development of the periodic table, is to be explained.

Concept introduction:

Aufbau principle states that the electrons are filled in various orbitals in the increasing order of their energies. It is also called as the building up principle.

The orbitals are filled in the increasing energy order as:

$1s<2s<2p<3s<3p<4s<3d<4p$

According to the periodic law, when the various elements are arranged in the increasing order of their atomic numbers, there is a systematic repetition of physical and chemical properties. The elements having similar electronic configuration are placed together in various groups, therefore showing repetition of properties among them.