What type of semiconductor is $CdS$?

Electrical conductivity of insulators is

In a good conductor,the energy gap between the conduction band and the valence band is:

Sodium has a body-centered cubic $(BCC)$ packing. If the distance between two nearest atoms is $3.7 \mathring{A}$,then its lattice parameter is.....$\mathring{A}$

On the basis of which principle are the band diagrams of solids classified into different types?

Statement-$1$: The temperature coefficient of resistance of an intrinsic semiconductor is negative.
Statement-$2$: As temperature increases,more charge carriers are released into the conduction band.