Define semiconductor?

What are holes in semiconductor?

Define resistivity of a conductor. Explain the variation of resistance with temperature in semiconductors.

What is an intrinsic semiconductor? How can this material semiconductor? How can this material be converted into p-type extrinsic semiconductor? Explain with the help of energy band diagrams?

What is meant by 'doping' in a semiconductor?

How can intrinsic semiconductor material be converted into n-type extrinsic semiconductor? Explain with the help of energy band diagrams?