- 2018: The conductivity of a semiconductor increases when it is doped with a substance whose atoms have (A) fewer valence electrons than the semiconductor atoms (B) more valence electrons than the semiconductor atoms (C) the same number of valence electrons as the semiconductor atoms (D) none of the above choices
The correct answer is (B).
A semiconductor is a material that has an intermediate electrical conductivity between that of a conductor and an insulator. When a semiconductor is doped with a substance whose atoms have more valence electrons than the semiconductor atoms, the extra electrons can move more easily through the semiconductor, resulting in an increase in conductivity.
