Question

What is the best semiconductor?
(a). Wood
(b). paper
(c). Silicon
(d). Copper

Answer 1

Hint: Semiconductors are materials which have conductivity intermediate between conductors and insulators. Their conductivity is explained by the distance between the conduction band and the valence band. There are different types of materials which are distinguishable on the basis of their properties, check which are the semiconductors based on their properties out of the options given.

Complete answer:
Semiconductors are materials which have conductivity better than the insulators but less conductivity than the conductors. In semiconductors, the distance between the valence and the conduction band is negligible while in insulators, the distance between valence band and conduction band is large but in conductors, the valence band and the conduction band overlap each other.
With temperature, the conductivity of semiconductors and insulators increase while the conductivity of conductors decrease.
Wood is an insulator as it shows all the properties of an insulator similarly, paper is also an insulator. Whereas copper is a metal and metal are conductors, Silicon is a metalloid, as it shows all the properties of a semiconductor, Silicon is a semiconductor.
Some other examples of semiconductors are germanium, Arsenic, Boron etc.
Therefore, Silicon is a semiconductor.

Hence the correct option is (c).

Note:
The space between the conduction band and the valence band is called the forbidden zone and no electron can exist in the forbidden zone. The conduction band contains the electrons which conduct electricity. Metalloids are materials which show properties which are intermediate to metals and non-metals. Metals are conductors of electricity while non-metals are insulators.