$1.$ The potential energy, E$,$ per Cs$+-$Cl$-$ ion pair within the CsCl

crystal depends on the interionic separation, r$,$ expressed

mathematically thus: E$($r$)=-$e$2$M$/(4$p$\backslash$epsi $0$r$)+$ B$/$rm$,$ where, e $=1\mathrm{.}6$ x

$10-19$ C$,$ M $=1\mathrm{.}763,\backslash$epsi $0=8\mathrm{.}85$x$10-12$ Fm$-1,$ B $=1\mathrm{.}192$ x $10-104$ Jm$9,$

or $7\mathrm{.}442$ x $10-5$ eV$($mm$)9,$ and m $=9,.$ Find the equilibrium

separation $($requ$),$ of the ions in the crystal and the ionic bonding

energy that is the ionic cohesive energy. Next, generate the

corresponding Energy$-$Separation plot for the cesium chloride solid.

Repeat exercise for the Force$-$Separation plot. All plots must be

carried out with specified Scales. $2.$ The van der Waals bonding in

solid argon can be expressed mathematically thus: E$($r$)=-$Ar $-6+$

Br $-12,$ where, A and B are constants. Given that A$=8\mathrm{.}0$ x $10-77$

Jm$6,$ and B $=1\mathrm{.}12$ x $10-133$ Jm$12.$ Calculate the bond length, requ,

and the bond energy in eV $($electron Volts$)$ for the solid argon.

Next, generate the corresponding Energy$-$Separation plots. Repeat

the exercise for the Force$-$Separation plot. All plots must be

carried out with specified Scales.