a) The required conductivity of an n-type silicon sample at T 300 K is to be 10 (-cm)1. What donor impurity concentration is required? What is the electron mobility corresponding to this impurity concentration? (b) A p-type silicon material is required to have a resistivity of 0.20 (-cm). What acceptor impurity concentra-tion is required and what is the corresponding hole mobility

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.