Assignment 3

  1. The shorter the wavelength, the [more, less] energy it has.
  2. The longest wavelength of light is how many nm?
  3. Which has the shorter wavelength, red or blue light?
  4. The shortest electromagnetic waves are called what?
  5. What molecule in our atmosphere absorbs ultraviolet?
  6. A [reflector, refractor] uses a lens to gather light.
  7. [Refractors, Reflectors] suffer from chromatic aberration.
  8. The largest refracting telescope in the world has a diameter of how many inches?
  9. Why are the largest telescopes reflectors instead of refractors?
  10. If you were to buy a telescope on a fixed budget a [refractor, reflector] would be the best choice.
  11. True or False: The most important property of a telescope is its magnifying power.
  12. What causes the stars to twinkle?
  13. Why is the Cassegrain focus so common for telescopes?
  14. The method of achieving greater resolving power by connecting several telescopes is called what?
  15. Each of the mirrors on  the VLT has a diameter of      m.
  16. What is meant by adaptive optics?
  17. What are the advantages of CCD’s over photographic plates?
  18. What is meant by a false-color image?
  19. When light passes through a prism red is bent [more, less] than blue.
  20. The radio telescope Arecibo, Puerto Rico has a diameter of how many meters?
  21. The Hubble Space Telescope has a diameter of how many inches?
  22. The orbiting Chandra telescope is designed to detect [infrared, x-rays].
  23. Why must infrared telescopes be cooled?
  24. The nucleus of an atom has a [negative, positive] charge.
  25. The element an atom belongs to depends on how many [protons, neutrons] are in its nucleus.
  26. Isotopes of the same element differ in how many [electrons, neutrons] it has.
  27. Suppose a carbon atom has five electrons going around it. The carbon atom is [neutral, ionized].
  28. What is meant by binding energy?
  29. An atom can become excited by a collision or what other method?
  30. Suppose a hydrogen atom has its electron in the second orbit. The atom is in the [ground, excited] state.
  31. What temperature is absolute zero on the Fahrenheit scale?
  32. For black body radiation, as the temperature increases the wavelength of maximum intensity shifts to [shorter, longer] wavelengths.
  33. If light composed of a continuous spectrum passes through a cool, low density gas the result will be an [absorption, emission] spectrum. [Hint: One of Kirchhoff’s laws.]
  34. When an electron falls to a lower orbit, it [emits, absorbs] a photon.
  35. Balmer absorption lines are produced by hydrogen atoms with their electron in the [first, second, third] energy level.
  36. [High, Medium, Low] temperature stars have Balmer lines.
  37. Which has the higher temperature, an F or a K spectral type star?
  38. What is the spectral type of the sun?
  39. Molecular bands are found in [cool, hot] stars.
  40. What is the most abundant element making up the sun?
  41. The Doppler effect works for motion [along the line of sight, perpendicular to the line of sight.]
  42. Suppose the absorption lines in a star’s spectrum are shifted to the red. The star is [approaching, receding].
  43.    The Hubble Space Telescope is about how many miles above the Earth?
  44. An Atom consists mainly of [mass, empty space].
  45. True or False: Cosmic rays are a form of electromagnetic radiation
  46. Which type of spectral type is cooler, the L or T dwarfs?