Chapter 2, Problem 25P

Interpretation Introduction

Interpretation:

For each of the following observations (a) the mass spectrum of molecular bromine shows three lines for the parent ion ${\left[{\text{Br}}_{\text{2}}\right]}^{\text{+}}$, (b) in the structure of solid bromine, each Br atom has one nearest neighbour at a distance of 227 pm, and several other next nearest neighbours at 331 pm, (c) in the salt formed from the reaction of ${\text{Br}}_{\text{2}}$ and ${\text{SbF}}_{\text{5}}$, the Br-Br distance in the ${\left[{\text{Br}}_{\text{2}}\right]}^{\text{+}}$ ion (215 pm) is shorter than in ${\text{Br}}_{\text{2}}$, are to be explained.

Concept Introduction:

Two or more species, if they possess the same number of electrons are called isoelectronic species. For example, ${\text{O}}^{\text{2-}}{\text{,F}}^{\text{-}}\text{,}{\text{Na}}^{\text{+}}\text{and}{\text{Mg}}^{\text{2+}}$ are isoelectronic species of each other

Atomic number (Z) = number of protons present in the nucleus of an atom of the element = number of electrons present in a neutral atom of the element

A chemical bond is a force of attraction which holds two atoms together.

Molecular orbitaltheory is a method for describing the electronic structure of molecules. This theory allocates electrons to molecular orbitals formed by the overlap of atomic orbitals.

Bond Order = ½ (number of bonding electron – number of antibonding electron)