1. Given what you have learned in today's lab, which has more energy, red light or blue light? With that in mind, which of the Balmer lines corresponds to the greatest change in energy level for the electron?

2. The hottest stars have temperatures of about 4x10⁴ K and the coolest have temperatures around 2x10³ K. What wavelengths of light do these stars emit if wavelength = 3x10⁷ Å / T (K)? How do these wavelengths compare to the wavelengths of light given off by the sun (surface temperature = 5800 K). Is the light visible? (Note: The human eye can see wavelengths between about 4500 and 6750 Å .)

3. If a person were to observe the brightest stars in the night sky with his or her naked eye, would that person be able to distinguish between hot stars and cool stars? Please explain.

4. The sun emits the highest intensity of radiation over the same wavelength range that the human (as well as many animals') eye is most sensitive over. Is this pure coincidence or is there an explanation for this. Consider a planet that is orbiting a star that is hotter than our sun. If creatures with "eyes" were to evolve in that planet, over what range of electromagnetic radiation would their "eyes" most likely be sensitive to?

5. How can an astronomer tell that most of the universe is hydrogen?

6. Do people radiate light? Could you see a person in a completely dark room? Why? How do we normally see other people and objects here on Earth?

Updated: 2001.10.08 (Monday) 22:41:22 EDT