Question

Which of the following is primarily used in semiconductors?
A. Alkali metals
B. Alkaline earth metals
C. Metalloids
D. Halogens
E. Rare earth metals

Answer 1

Hint: In order to answer this question, we should know about semiconductors. Semiconductors materials are those which have an electrical conductivity falling between that of a conductor and an insulator. From the given options, we need to identify that which has an electrical conductivity like a conductor as well as an insulator.

Complete answer:
Let us understand the semiconductors in a complete detail.
Semiconductors are those materials which have electrical conductivity which falls between that of a conductor such as metals and an insulator such as glass, rubber etc. The most used semiconductor materials are silicon, germanium, and gallium arsenide. Germanium was the earliest semiconductor that was used. The number of valence electrons determines its conductivity.
For the given question, Metalloids are primarily used in semiconductors. The reason is that the metalloids are the chemical elements which have properties in between those of metals and non-metals. In other words, we can say that they are the mixture of metals and non-metals. We know that metals are the good conductor of electricity whereas non-metals are not. So, the electrical conductivity of metalloids falls between the conductor and that of an insulator. This is the reason that metalloids are semiconductors because they are neither poor conductors nor good conductors.
The correct answer is option (C).

Note:
It should be noted that all the elements that are recognized as metalloids have been used as semiconductors in solid state electronic industries. Also, the conductivity of the semiconductors are improved by the means of adding impurities or we can say doping of the crystal structure.