Using the electron drift mobility from Hall $-$ effect measurement

$({}_d)Cu=3\mathrm{.}2{10}^{-3}\frac{m^2}{V}.s,$ determine the average number of electrons contributes to the

free electron gas per copper atom in solid.

A$.1\mathrm{.}15e$

B$.3\mathrm{.}16e$

C$.1\mathrm{.}36e$

D$.3\mathrm{.}2e$

E$.8\mathrm{.}5$eUsing the electron drift mobility from Hall $-$ effect measurement

$({}_d)Cu=3\mathrm{.}2{10}^{-3}\frac{m^2}{V}.s,$ determine the average number of electrons contributes to the

free electron gas per copper atom in solid.

A$.1\mathrm{.}15e$

B$.3\mathrm{.}16e$

C$.1\mathrm{.}36e$

D$.3\mathrm{.}2e$

E$.8\mathrm{.}5e$