Amaterial that only conducts electric current under certain conditions is a(n)
a. conductor.
b. insulator.
c. semiconductor.
d. vacuum tube.

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline

What component of earth’s atmosphere exists entirely as a result of photosynthesis?