Which best describes a p-type semiconductor? a) They have holes that are positively charged. b) They have weakly bound electrons that can flow easily. c) They emit electrons at one end of a vacuum tube. d) They emit electron beams that strike phosphors.

They have holes that are positively charged

Explanation:

There are two types of semiconductors i.e. p-type and n-type.

p-type is a type of semiconductor that is formed when a trivalent impurity is added to an intrinsic semiconductor like silicon or germanium. Boron (B), Gallium (Ga), Indium(In), Aluminium(Al) etc are trivalent impurities. Due to this combination, a large number of holes are created in it.

Hence, p-types of semiconductors have holes that are positively charged.

d) physical means can be used to separate the components of air.