Chapter 11, Problem 11B.6DQ

(i)

Interpretation Introduction

Interpretation:

The geometry of ${\text{BeF}}_{\text{2}}$ has to be stated.  Whether the ${\text{Be}}^{\text{19}}{\text{F}}_{\text{2}}$ molecule exists in ortho and para form or not is to be predicted.

Concept introduction:

A rotational spectrum is a spectrum in which only the rotation of molecule changes.  For a molecule to exhibit pure rotational spectrum, the molecule must possess a permanent electric dipole moment.  Nuclear statics is the selective existence of rotational states that stems from the Pauli principle.  Whenever a rotation interchanges equivalent nuclei, the nuclear statics is takes into account.

(ii)

Interpretation Introduction

Interpretation:

Whether the fluorine nuclei are fermions or bosons is to be predicted.

Concept introduction:

If the spin value $\text{I=1}$, then the nuclei are called bosons.  However, if the spin value $\text{I=}\frac{\text{1}}{\text{2}}$, then the nuclei are called fermions.