Chapter 8, Problem 8.93QE

Interpretation Introduction

Interpretation:

The number of unpaired electrons for a ${\text{Cr}}^{4+}$ cation has to be determined.

Concept Introduction:

The electronic configuration is defined as the distribution of electrons in various atomic orbitals of the atom. Electrons are filled in orbitals in accordance with three rules: Aufbau principle, Hund’s rule, and Pauli’s exclusion principle. Aufbau principle states that electrons are filled in the orbitals from lower to higher energy level as follows:

  $1s<2s<2p<3s<3p<4s<3d<4p<5s<4d<5p<6s<4f<5d<6p<7s$

Hund’s rule states that initially each orbital is singly occupied and then pairing occurs and Pauli’s exclusion principle states that the spin of two electrons in one orbital is always different.

Ions are formed by gain or loss of electrons. When an electron is lost from the neutral atom, it forms a positively charged ion called cation. An anion is formed when the neutral atom gains an electron.