Light Spectrum

Astronomy Today.  Chaisson/McMillan. Prentice Hall. 1997. Chapters 3 and 4. pgs. 52 - 93.

 (Individual bookwork)  Warm Up: Define each term.

  1. Photosynthesis
  2. Plastids
  3. Pigments
  4. Chloroplast
  5. Chlorophyll
(Think, 15-30s, share ideas in a small trio group)

Question:   Why do leaves change color in the fall?

(Lecture, 15-20m)

I.  Light and Radiation.

Radiation - way in which energy is transmitted through space.
Waves, light, radiation, rays all mean the same thing.

a. visible light -
human eye sensitivity - light enters eye, cornea and lens focus it onto the retina, triggering chemical reactions sending electrical impulses to the brain, producing the sensation of sight.

b. invisible radiation - undetected

  1. radio -
  2. infrared -
  3. ultraviolet -
  4. x rays -
  5. gamma rays -