Why the valence band in semiconductors is partially empty and the conduction band is partially filled at room temperature?

In an intrinsic semiconductor, the number of conduction electrons is 7 × 10¹⁹ m³. Find the total number of current carriers in the same semiconductor of size 1 cm × 1 cm × 1 mm.

The energy gap of silicon is 1.14 eV. What is the maximum wavelength at which silicon will begin absorbing energy?

The energy of a photon of sodium light (λ = 589 nm) equals the bandgap of semiconducting material. Find:

The minimum energy E required to create a hole-electron pair. (5890 A⁰)

The value of E/kT at a temperature of 300 K. (81)

A P-type semiconductor has acceptor level 57 meV above the valence band. What is the maximum wavelength of light required to create a hole? (217100 A⁰)

Least paramagnetic property is shown by
Fe
Mn
Ni
Cu

Which of the following gives a red precipitate with AgNO₃ ?

KI

K₂CrO₄

NaBr

NaNO₃ .

How many d electrons are in present Cr²⁺ ion
4
5
6
3

Which one of the following sets correctly represents the increase in the paramagnetic property of ions

Cu⁺²>V⁺²>Cr⁺²>Mn⁺²

Cu⁺²< Cr⁺²< V⁺²< Mn⁺²

Cu⁺²< V⁺²< Cr⁺²< Mn⁺²

V⁺²< Cu⁺²< Cr⁺²< Mn⁺²

What is Dielectric?