What is the relation between the number density of holes $(n_h)$ and free electrons $(n_e)$ in an intrinsic semiconductor at room temperature?

$A$ $P$-type semiconductor is:

In a pure silicon, the number of electrons and holes per unit volume is $1.6 \times 10^{16} \,m^{-3}$. If silicon is doped with Boron in a way that the hole density increases to $4 \times 10^{22} \,m^{-3}$, then the electron density in the doped semiconductor will be:

In $p-$type semiconductor,the majority charge carriers 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: $h = 6.6 \times 10^{-34} \, J \, s$, $c = 3 \times 10^8 \, m/s$, $1 \, eV = 1.6 \times 10^{-19} \, J$)

$A$ pure $Si$ crystal has $4 \times 10^{28}$ atoms per $m^3$. It is doped with $1 \text{ ppm}$ concentration of antimony. The number of free electrons available will be