Explain concept of valence band and conduction band in solid crys… - Vidyadip

Question

Explain concept of valence band and conduction band in solid crystal.

✓

Answer

A. Valence band (V.B):

The topmost occupied energy level in an atom is the valence level. The energy band formed by valence energy levels of atoms in a solid is called the valence band.
In metallic conductors, the valence electrons are loosely attached to the nucleus. At ordinary room temperature, some valence electrons become free. They do not leave the metal surface but can move from atom to atom randomly.
Such free electrons are responsible for electric current through conductors.

B. Conduction band (C.B):

The immediately next energy level that electrons from valence band can occupy is called conduction level. The band formed by conduction levels is called conduction band.
It is the next permitted energy band beyond valence band.
In conduction band, electrons move freely and conduct electric current through the solids.
An insulator has empty conduction band.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Answer the following in Detail" from Semiconductors→Semiconductors — all question types→Physics STD 11 Science question papers→Maharashtra Board STD 11 Science question papers→Maharashtra Board question paper generator→

Similar questions

The value of $G$ in $\text{C.G.S}$ system is $6.67 \times 10^{-8} dyne \ cm^2 g^{-2}.$ Calculate its value in $\text{S.l.}$ system.

Explain what is doping.

Explain the variation of acceleration, velocity and distance with time for an object under free fall.

Using expression for change in potential energy, show that gravitational potential energy of the system of object of mass $m$ and the Earth with separation of $r$ is, $-\frac{ GMm }{r}$

The sound emitted from the siren of an ambulance has frequency of $1500\ Hz$. The speed of sound is $340\ m/s$. Calculate the difference in frequencies heard by a stationary observer if the ambulance initially travels towards and then away from the observer at a speed of $30\ m/s$.

Drive expression for electric intensity at a point on the equator of an electric dipole.

Discuss the effect of external voltage on the width of depletion region of a p-n junction.

Derive the formula for kinetic energy of a particle having mass $m$ and velocity $v$ using dimensional analysis

A monochromatic ray of light is incident at $37^\circ $ on an equilateral prism of refractive index $3/2$. Determine angle of emergence and angle of deviation. If angle of prism is adjustable, what should its value be for emergent ray to be just possible for the same angle of incidence.

Explain with examples the universal law which states that “Every system always configures itself in order to have minimum potential energy or every system tries to minimize its potential energy”.