In our location in the Milky Way, the galactic disk is only about ________ ly thick
A) 10 B) 100 C) 1,000 D) 10,000 E) 100,000
C
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When light is either reflected or refracted, the quantity that does not change in either process is its
a. direction of travel. b. dispersion. c. frequency. d. speed. e. wavelength.
Which of the following is not an observed characteristic of the cosmic microwave background?
A) It contains prominent spectral lines of hydrogen, the primary chemical ingredient of the universe. B) It has a perfect thermal radiation spectrum. C) Its temperature is the same everywhere, except for small variations at the level of 1 part in 100,000. D) Its temperature is a little less than 3 Kelvin (3 degrees above absolute zero).
Which major atmospheric component is chiefly a product of life processes?
A) Carbon dioxide B) Water C) Oxygen D) Hydrogen sulfide E) Nitrogen
What is the energy of a photon of light of wavelength 4.80 × 10^–7 Hz? h = 6.63 × 10^–34 J?s and 1 eV = 1.6 × 10^–19 J
a. 144 eV b. 1.38 eV c. 2.59 eV d. 2.21 eV