Consider a nonionized phosphorus donor atom in a si crystal.
(a) what is the "bohr radius" of the resulting "atom? "
(b) estimate how many si atoms are contained within a sphere of this "bohr radius"?
(c) estimate how high the concentration of impurities would have to be for the "bohr radii" to overlap, and what would you expect to happen in this case?

What are the theoretical properties of a gas at a temperature of 0 kelvin?

While you are driving in the lane next to the curb on a multi-lane road the car on your left suddenly moves toward you lane. they are about toy crash into your front fender. you

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e