Chapter 7, Problem 22PE

Interpretation Introduction

Interpretation:

The valence shell electron configuration for the given elements and the number of valence electrons for each element is to be determined.

Concept Introduction:

Valence shell is the outermost shell of an atom, only the electrons present in the valence shell participate in the chemical bonding.

An element’s chemical properties can be determined by the valence electrons.

The electron configuration of an atom contributes to their physical and chemical properties. It helps in the better understanding of the structure of an atom and the nature of the electrons contained within that atom.

Three rules that should be followed to fill the atomic orbitals by electrons:

Rule 1: The lowest energy orbitals fill first, filling pattern is $\text{1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p etc}\text{.}$ The entire subshell of a particular orbital type filled before moving to the next subshell of higher energy.

Rule 2: Pauli Exclusion Principle- Only two electrons of opposite spin are permitted per orbital.

Rules 3: Hund’s Rule – The orbitals of the same energy are each filled with one electron of same spin before filling any with a second electron.