In which of the following situations is the photoelectric effect being demonstrated? A.
The color of a substance is determined by the wavelength of electromagnetic radiation that is reflected off of its surface.
B.
A photon of light travels at the speed of light in a vacuum but moves slightly slower through a medium made of matter.
C.
An electron moves through a sea of electrons within a block of aluminum atoms when a voltage is applied to the metal.
D.
An electron within an atom absorbs energy when it is hit by a photon and jumps to a higher energy level within the atom.