1. Galaxies and the Universe
Chapter 30 Review
Galaxies and the Universe

2. What characteristic of radio waves makes them useful for determining the shape of a galaxy?
their long wavelength
their high frequency
their easy visibility
their variable energy

3. What method allows astronomers to locate the structures circled in the diagram?
recording radio waves
observing RR Lyrae variables
measuring infrared radiation
observing hydrogen emission spectra

4. Which of the following is a characteristics of a Population II star?
trace amounts of heavy elements
age of less than 10 billion years
located in disk arms
found in spiral galaxies

5. The Milky Way and the Andromeda are both________.
stars
galaxies
nebulae
quasars

6. A scientist who discovered a galaxy could use the following diagram to classify the galaxy according to its
shape
age
color
size

7. Which ratio best expresses the mass of the Sun compared to the mass of the Milky Way?
1: 100 billion
1: 100 million
1: 100 trillion
1: 100 thousand

8. Which line on the graph shows the relationship between the size and brightness of a variable star?

9. The pulsation period of four variable stars is indicated on the diagram. Which of the stars in a Cepheid Variable? A B C D

10. Which sentence best summarizes Hubble’s Law?
The greater the distance to a galaxy, the greater its velocity.
The greater the distance to a galaxy, the brighter its halo.
The greater the distance to a galaxy, the greater its age.
The greater the distance to a galaxy, the greater its mass.

11. Other galaxies were first believed to be ____.
nebulae or star clusters within the Milky Way
quasars outside the Milky Way
constellations within the Milky Way
the Andromeda galaxy

12. Elliptical galaxies are divided into subclasses based on ____.
their elongated shapes
the length of their diameters
the ratio of their major and minor axes
the length of their spiral arms

13. Cosmic background radiation has a wavelength of approximately 1 mm, which makes it ____.
gamma ray radiation
microwave radiation
X-ray radiation
infrared radiation

14. If the average density is higher than the critical density, the universe is ____.
closed
open
flat
round

15. Recent observations show that the rate of expansion of the universe is ____.
slowing down
stabilizing
constantly changing
speeding up

16. Study of the universe inflationary universe cosmology Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

17. Core of a galaxy in which highly energetic objects or activities are located
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

18. Gigantic formation of clusters of galaxies hundreds of millions of light-years in size
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

19. A value of approximately 70 kilometers per second per megaparsec
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

20. States that the universe began as a point and has been expanding ever since
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

21. Proposes that the universe looks the same on large scales to all observers and that it has always looked that way
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

22. Persistent noise discovered in 1965 that is caused by weak radiation from all directions in space
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

23. Model that says the universe began as a fluctuation in a vacuum and expanded very rapidly for a fraction of a second before settling into a more orderly expansion
inflationary universe
cosmology
Big Bang theory
cosmic background radiation
steady-state theory
Hubble constant
active galactic nucleus
superclusters

24. Normal spiral E7
Irr a c SO EO S SB

25. Barred spiral E7
Irr a c SO EO S SB

26. Tightly wound arm and large, bright nucleus
Irr a c SO EO S SB

27. Loosely wound arms and a small, dim nucleus
Irr a c SO EO S SB

28. Flat disks that do not have spiral arms
Irr a c SO EO S SB

29. Round elliptical E7
Irr a c SO EO S SB

30. Very elongated elliptical
Irr a c SO EO S SB

31. Irregular galaxy E7
Irr a c SO EO S SB

32. Variable stars get brighter as they get larger.
True
False

33. The Sun is classified as a Population II star.
True
False

34. RR Lyrae and Cepheid are two categories of variable stars.
True
False

35. The Local Group is the galactic group that includes the Milky Way.
True
False

36. The galaxy in the diagram is categorized as E0 based on its shape.
True
False

37. The Milky Way and Andromeda are larger than other galaxies in the Local Group.
True
False

38. Redshift is used as evidence that the universe is contracting.
True
False

39. The equation v = Hd shows the relationship between the speed at which a galaxy moves and its distance.
True
False

40. The shaded area of the circle graph represents the percent of the universe composed of dark matter.
True
False

41. On a graph, Hubble’s law is represented by a straight line.
True
False

42. By measuring a star's period of pulsation, astronomers can determine its luminosity and calculate how far away a variable star must be to appear as dim or as bright as it does.
True
False

43. Astronomers have determined the shape of the Milky Way by using gamma waves because they penetrate the interstellar gas and dust without being scattered or absorbed.
True
False

44. Edwin Hubble's discovery of RR Lyrae variable stars in the Great Nebula in the Andromeda constellation proved the existence of galaxies outside the Milky Way.
True
False

45. The halo and bulge of the Milky Way are made of old stars which suggests that the halo and bulge formed first.
True
False

46. A(n) SBc galaxy is a normal spiral with loosely wound arms and a small, dim nucleus.
True
False

47. The farther away from Earth a galaxy is, the slower it is moving.
True
False

48. There are 35 known members of the Local Group, of which the Milky Way and Andromeda galaxies are the two largest.
True
False

49. The redshift in many quasars is very large, which means that those quasars are far away.
True
False

50. Most galaxies in the inner region of a large cluster are spirals.
True
False

51. Studies provide evidence that there is a great amount of unseen matter called dark matter composed of dim stellar remnants that have no mass.
True
False

52. Edwin Hubble measured the redshifts and distances of many galaxies and found that the redshift of a galaxy depends on its distance from Earth.
True
False

53. Cosmic background radiation provides information about conditions now in the expansion of the universe.
True
False

54. A key goal of the Fermilab is to gather data that would help to pinpoint the value for H, the Hubble constant.
True
False