When the conductivity of a semiconductor is only due to breaking of covalent bonds, the semiconductor is called

For a $p-$type semiconductor,which of the following statements is true?

$A$ pure $Si$ crystal has $5 \times 10^{28}$ atoms $m^{-3}$. It is doped with $1 \, ppm$ concentration of pentavalent $As$. The number of holes is (Take $n_i = 1.5 \times 10^{16} \, m^{-3}$)

The charge carriers in a $p$-type semiconductor are

In a $P$-type semiconductor, the acceptor energy level $E_A$ is located $57 \, meV$ above the valence band. The maximum wavelength required to create a hole is ....... $\mathring{A}$. (Given: $h = 6.6 \times 10^{-34} \, J \, s$, $c = 3 \times 10^8 \, m/s$, $1 \, eV = 1.6 \times 10^{-19} \, J$)

What will be the conductivity of a pure silicon crystal at $300 \ K$ temperature,if the electron-hole pairs per $cm^3$ is $1.072 \times 10^{10}$ at this temperature,$\mu_e = 1350 \ cm^2/V \cdot s$ and $\mu_h = 480 \ cm^2/V \cdot s$?