$1\mathrm{.}25$ The Debye temperature.

${}_D=\frac{n{}_D}{k_B}$

is more commonly tabulated and determined thin is the Debye frequency becaute of irs relationship to the thernodynamic properties of solids.

$($a$)$ Calculate the Debye frequencies of the elemental folids listed in Tuble $1,3$ in Ha$.$ meV. and $c{m}^{-1}.$

$($b$)$ Calculate the mean phonon occupation number at the Debye frequency and room temperature for each of these materials at $100,300,$ and $1000K.$