Problem $5$: Semiconductor Dopants

$($a$)$ What type of semiconductor is obtained for gallium nitride with magnesium doping?

$($b$)$ If an electron is in a shallow donor level located $20$ meV below the conduction band, then find the

temperature in Celsius corresponding to this energy $($use kB $=8\mathrm{.}62105$ eV$/$K$).$ Would the donated

electrons be in the conduction band at room temperature and why?