Choose the correct statement. In conductors,

The band gap in Germanium and Silicon in $eV$ respectively is

Assertion : The resistivity of a semiconductor increases with temperature.
Reason : The atoms of a semiconductor vibrate with larger amplitude at higher temperatures,thereby increasing its resistivity.

This question has Statement $1$ and Statement $2$. Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement $1$ : $A$ pure semiconductor has a negative temperature coefficient of resistance.
Statement $2$ : On raising the temperature,more charge carriers are released into the conduction band.

The state of the energy gained by valence electrons when the temperature is raised or when an electric field is applied is called as:

State the conductivity of metals and resistivity of insulators.