Exam: Unit 1, The Universe and its Stars, HS-ESS1A NAME_______________________ Class ______
Directions: Choose the alternative that best completes the statement or answers the question.
1) Which of the following colors has the longest wavelength?
A) violet B) red C) orange D) green E) blue
2) Which of the following is NOT considered a form of electromagnetic radiation?
A) gamma rays B) x-rays C) gravity D) visible light E) radio waves
3) The type of spectrum produced by a common light bulb is a ________.
A) bright-line (emission) spectrum
B) dark-line (absorption) spectrum
C) continuous spectrum
D) all of the above
E) none of the above
4) The spectra of most stars are of this type.
A) continuous spectrum
B) bright-line (emission) spectrum
C) dark-line (absorption) spectrum
D) all of the above
E) none of the above
5) As the temperature of a radiating surface is increased ________.
A) the total amount of energy emitted increases
B) a larger portion of the energy is radiated at longer wavelengths
C) a larger portion of the energy is radiated at shorter wavelengths
D) both A and B
E) both A and C
6) The most explosive events to occur on the Sun are ________.
A) umbras B) filaments C) solar winds D) solar flares E) sunspots
7) To determine whether a celestial body is approaching or receding from Earth, astronomers employ ________.
A) telescopic imaging
B) the Stefan-Boltzmann law
C) high speed radar
D) the Doppler principle
E) Einstein's equation
8) The source of the Sun's energy is ________. 8) _______
A) chemical burning B) nuclear fission C) potential energy D) nuclear fusion E) heat of contraction
9) The most conspicuous features on the surface of the Sun are dark areas called ________.
A) helium lines B) spicules C) granules D) flares E) sunspots
10) The Sun's surface has a grainy texture produced by numerous bright markings called ________.
A) spicules B) umbras C) sunspots D) granules E) helium lines

11) The Sun produces energy by converting ________.
A) carbon monoxide to oxygen nuclei
B) oxygen nuclei to nitrogen nuclei
C) helium nuclei to hydrogen nuclei
D) oxygen nuclei to carbon dioxide
E) hydrogen nuclei to helium nuclei
12) Streams of protons and electrons emitted from the Sun produce ________.
A) granules B) prominences C) the solar wind D) quasars E) plages
13) During periods of high solar activity, huge cloudlike structures that appear as great arches extending from the Sun are
often produced. These solar features are called ________.
A) prominences B) quasars C) the solar wind D) spicules E) plages
14) One of the most common units used to express stellar distance is the ________.
A) light-year B) kilometer C) mile D) meter
15) The measure of a star's brightness is called its ________.
A) intensity B) color C) magnitude D) parallax
16) The distance to stars can be determined from ________.
A) emission nebulae B) fluorescence C) stellar mass D) stellar parallax
17) Which one of the objects listed below has the largest size?
A) nebula B) stars C) galaxies D) globular clusters
18) Our galaxy is called the ________.
A) Orion galaxy B) Pleiades galaxy C) Milky Way galaxy D) Panorama galaxy
19) Which color stars have the highest surface temperature?
A) yellow B) orange C) blue D) red
20) Which color stars have the coolest surface temperature?
A) orange B) yellow C) red D) blue
21) Which main-sequence stars are the most massive?
A) blue B) red C) yellow D) orange
22) Which main-sequence stars are the least massive?
A) orange B) yellow C) blue D) red
23) Possibly the most cataclysmic event to occur in nature is ________.
A) hydrogen burning B) electron degeneration C) a nova D) a supernova
24) The most dense stars known to exist are ________.
A) red dwarfs B) white dwarfs C) black holes D) neutron stars
25) These stars are produced during a supernova event.
A) black hole B) red giant C) white dwarf D) main-sequence star
26) A star in which light cannot escape because of the immense gravitational pull at its surface is called a ________.
A) red giant B) white dwarf C) black hole D) main-sequence star

27) The final stage in the evolution of the most massive stars is a ________.
A) white dwarf B) main-sequence star C) black hole D) red giant
28) The Sun belongs to this class of stars.
A) white dwarf B) red giant C) main-sequence star D) black hole
29) The point in stellar evolution when a star has used up all its fuel and is radiating away its remaining thermal energy as light is the ________ stage.
A) red giant B) main-sequence star C) white dwarf D) black hole
30) Most stars are in this stage of evolution.
A) red giant B) black hole C) main-sequence star D) white dwarf
31) The final stage for a star which is as massive as the Sun is a ________.
A) red giant B) black hole C) main-sequence star D) black dwarf
32) When a main-sequence star has exhausted the fuel in the inner region, it becomes a ________.
A) black hole B) main-sequence star C) black dwarf D) red giant
33) A first magnitude star is ________ times brighter than a 5th magnitude star.
A) 40 B) 100 C) 10 D) 5
34) Hubble's law states that galaxies are receding from us at a speed that is proportional to their ________.
A) orientation B) mass C) distance D) volume
35) The discovery that the universe appears to be expanding led to a widely accepted theory called ________.
A) the Doppler effect B) the Big Bang C) Einstein's Law D) Hubble's Law
36) Based on the observed red shifts in the spectral lines of distant galaxies, astronomers conclude that ________.
A) the universe is expanding B) the universe is contracting
C) the universe is in a steady state D) Earth is in the center of the universe
ESSAY. Write your answer in the space provided or on a separate sheet of paper.
Critical Thinking and Discussion. Use complete sentences, correct spelling, and the information presented in Chapter 24 to answer the questions below.
37) How do we calculate or determine the distances to stars? What units do we use and what are the limitations (if any) of the method used for such calculations?
38) Label the Giant and Supergiant stars, the Main Sequence stars, and the White dwarf stars on the H-R diagram below.

39) Briefly explain the sequence of events that are illustrated in Figure 24.11 below.
Critical Thinking and Discussion. Use complete sentences, correct spelling, and the information presented in Chapter 23 to answer the questions below.
40) Discuss the features and characteristics of the Sun? Are they thought to be unique to the Sun or are they typical of other stars? How do any of these structures relate to the process of nuclear fusion which is thought to produce the Sun's energy?

25) A
26) C
27) C
28) C
29) C
30) C
31) D
32) D
17) C
18) C
19) C
20) C
21) A
22) D
23) A
24) C
33) A
34) C
35) B
36) A
8) D
9) E
10) D
11) E
12) C
13) A
14) A
15) C
16) D
1) B
2) C
3) C
4) C
5) E
6) D
7) D
38) See Figure 24.7 in Earth Science, 12e.
37)
39)
40)