Question

Which of the following is true about semi-conductors: A. Exposing a crystal of a semiconductor to heat or light starts displacing valence electrons which then move throughout the crystal B. A material is classified as a semiconductor if its resistance to the flow of electric current is too low to permit it to be called a conductor C. Neither free electrons nor holes are considered charge carriers in a semi-conductor D. Gold and silver are important semiconductors

Answer 1

The answer is b 100%

Answer 2

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B. A material is classified as a semiconductor if its resistance to the flow of electric current is too low to permit it to be called a conductor.

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• Semiconductors contain a forbidden gap between the valence band and the conduction band, in which electrons energy levels are not allowed.
• The resistance of semiconductors decreases as their temperatures increases, which is opposite to how metals or other conductors behave.