The greatest cost per ton involved in buying coal for use in ...

[javeds]

The greatest cost per ton involved in buying coal for use in power plants is most likely for
 
  a. the mineral rights for the land on which the mine is built.
  b. transportation of the coal to the power plant from the mine.
  c. strip mining coal from the surface.
  d. mining coal from underground.
  e. reclamation of old strip mine sites.

Question 2

Atoms are mostly empty space.
 
  What will be an ideal response?

[jesse.fleming]

Answer to Question 1

D

Answer to Question 2

This is true, because the atom's edge is defined by the outermost electron's
position, and the rest of the atom has only occasional electrons and the nucleus at the center.
We might think that the probability density fills the space between the outer edge of the
atom and the nucleus. However, if we consider the probability density, we expect that it isn't
really there, it's more like the ghost of the electron.