Chapter 5, Problem 85A

Interpretation Introduction

Interpretation : The two bar magnets placed pointing in the same direction alongside each other is like trying to place two electrons into the same orbital is to be explained.

Concept Introduction : The quantum mechanical model explains the wave functions of hydrogen atoms called atomic orbitals.

Answer to Problem 85A

Magnets of the same direction repel while the electrons of the same spin into the same orbitals push each other and occupy other orbitals.

Explanation of Solution

The two bar magnets pointing in the same direction would repel each other.

According to Pauli’s exclusion principle, in order for two electrons to coexist in the same orbital, their spins must be opposing.

This implies that the two electrons must have the opposite spin despite having the same values of the three quantum numbers n, l, and m_l.

Similar to the magnet, electrons of the same spin also would push each other and be unable to occupy the same spin in an orbital.