Chapter 12, Problem 92E

Interpretation Introduction

Interpretation:Number of unpaired electrons present in first row of transition series should be determined.

Concept introduction:The process by which electrons are distributed in molecular or atomic orbitals is termed as electronic configuration and is arranged in accordance to Aufbau principle. Hund’s rule of multiplicity states that electrons are filled singly in an orbital initially and then pairing occurs with different spin. Thus atomic orbital is filled in accordance to this rule.

The electrons that are present in the outermost shell of an atom are termed as valence electrons. In accordance to Aufbau principle electrons are filled in lower energy level and than to higher level. The electrons are arranged in order from higher energy level to lower level is as follows:

  $s>p>d>f$

Electrons in orbitals are arranged as follows:

  $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}4d^{10}5s^2$

Total number of electrons occupied in each orbital is as follows:

  $\begin{array}{ccccc}\text{Orbital}& s& p& d& f\\ \text{Total electrons}& 2& 6& 10& 14\end{array}$