The intrinsic semiconductor becomes an insulator at

When the temperature of a semiconductor is increased,its resistance and electric conductivity respectively.

What is the relationship between the number density of free electrons $(n)$ and temperature $(T)$ in a semiconductor?

Explain with a diagram how current flows due to electrons and holes in a pure semiconductor.

Explain the crystalline structure by writing the electronic configuration of elementary semiconductors.

Carbon, silicon, and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $(E_g)_C$, $(E_g)_{Si}$, and $(E_g)_{Ge}$ respectively. Which one of the following relationships is true in their case?