(Explain what happens when a pigment molecule is struck by electromagnetic radiation in the visible light spectrum.)
pigments are molecules that absorb electromagnetic radiation. For example, the chlorophyll pigment in plants absorbs blue and red light, which is why they reflect green light (since green is the color not absorbed). Another example is melanin, which is the pigment that darkens the skin of people. Melanin absorbs UV to protect the skin. A pigment molecule struck by EM radiation in the visible region may absorb some of the light depending on what pigment it is.
