Answer Key
Concepts and Challenges in Earth Science, Teacher’s Resources CD-ROM
(c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. The Sun and Other Stars: CHAPTER 18, page 20
CHAPTER 18: THE SUN AND OTHER
STARS
18-1 How are stars formed?
Lesson Review
1. d 2. g 3. a 4. e 5. c 6. b 7. f 8. h
Skill Challenge
A. Gravity causes a nebula to contract and spin.
B. Nebula flattens into a disk, and the material at the
center of the disk forms a protostar. C. Protostar
continues to contract and nuclear reactions begin to
give off light and heat. It has become a star.
18-2 How is spectroscopy used to study
stars?
Lesson Review
1. a different 2. light 3. true 4. medium-hot
5. true 6. hottest
Skill Challenge
1. hotter 2. hotter 3. red 4. red 5. white-yellow
6. blue 7. Students should color the Sun yellow.
18-3 What is magnitude?
Lesson Review
1. brighter 2. sixth-magnitude 3. absolute
magnitude 4. scale 5. temperature
6. first-magnitude 7. close 8. magnitude
9. third-magnitude 10. apparent magnitude
Skill Challenge
1. equal to 2. less than 3. Star A is farther away
from Earth than Star B.
18-4 How are stars classified?
Lesson Review
1. increases 2. white dwarfs 3. main sequence
4. absolute magnitude 5. red giants 6. supergiants
Skill Challenge
1. C 2. A 3. D 4. B 5. the relationship between a
star’s absolute magnitude and its surface
temperature, or color
18-4 How are stars classified?
Enrichment Activity: Star Temperature and Color
PART A
1. Arcturus should be colored yellow. 2. Betelgeuse
should be colored red; supergiant 3. Sirius should
be colored white. 4. The North Star should be
colored yellow or white-yellow. 5. Rigel should be
colored blue. 6. Procyon B should be colored
yellow or white-yellow; white dwarf
PART B
a. 2 b. 4 c. 3 d. 5 e. 1 f. 6
18-5 What is a star’s life cycle?
Lesson Review
1. mass 2. supernova 3. true 4. hydrogen 5. true
6. nova 7. true 8. neutron star
Skill Challenge
1. nebula 2. protostar 3. main sequence star 4. red
giant 5. planetary nebula 6. white dwarf 7. black
dwarf 8. supernova 9. neutron star
10. black hole
18-6 What kind of star is the Sun?
Lesson Review
1. gases 2. core 3. chromosphere 4. boundaries
5. energy 6. corona 7. color sphere 8. photosphere
9. atmosphere 10. visible surface
Skill Challenge
A: corona B: chromosphere C: photosphere
D: core
18-7 What is the surface of the Sun like?
Lesson Review
PART A
1. the Sun 2. true 3. cooler 4. sunspots 5. true
PART B
1. dark, cool areas on the Sun’s surface 2. an
eruption of electrically charged particles from the
surface of the Sun 3. stream of gas that shoots high
above the Sun’s surface
Skill Challenge
1. about 140 2. 200 3. 1780, about 1837, 1870, and
1959 4. low 5. about 40
Answer Key
Concepts and Challenges in Earth Science, Teacher’s Resources CD-ROM
(c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. The Sun and Other Stars: CHAPTER 18, page 21
18-8 How does the Sun produce
energy?
Lesson Review
1. energy 2. Albert Einstein 3. combine 4. matter
5. hydrogen 6. nucleus 7. fusion 8. speed of light
9. Sun 10. less than
Skill Challenge
1. c = speed of light 2. E = energy 3. m = mass
4. how a small amount of matter can be changed into
a large amount of energy
18-8 How does the Sun produce
energy?
Enrichment Activity: Sunspot Activity
PART A
Check to see that students’ graphs match the
numbers in the data table. The years should be on
the x-axis and the number of sunspots should be on
the y-axis.
PART B
1. 1989 2. 1996 3. Yes, there is a pattern. The
number of sunspots decreased from its peak in 1989,
then gradually increased. 4. greater than 10
5. greater than 60 6. 1989; The greatest number of
sunspots occurred during that year.
18-9 What are constellations?
Lesson Review
1. g 2. f 3. e 4. b 5. c 6. h 7. a 8. d
Skill Challenge
Check students’ diagrams for accuracy. The Little
Dipper has three stars in the handle and four in the
cup. The North Star is the first star in the handle.
Three bright stars make up Orion’s belt. Betelgeuse
is under Orion’s arm, and Rigel is in Orion’s knee.
18-10 What are galaxies?
Lesson Review
1. Elliptical galaxy 2. Irregular galaxy 3. Spiral
galaxy 4. Elliptical galaxy, Irregular galaxy, Spiral
galaxy 5. Irregular galaxy 6. Elliptical galaxy
7. Spiral galaxy 8. Irregular galaxy 9. Elliptical
galaxy, Irregular galaxy, Spiral galaxy 10. Spiral
galaxy 11. Spiral galaxy
Skill Challenge
Galaxy name: Milky Way Galaxy
Facts: spiral galaxy; contains more than 100,000
billion stars; is about 100,000 light years in diameter
18-11 What else do we know about the
universe?
Lesson Review
1. universe 2. black hole 3. Big Bang 4. quasar
5. colliding galaxy 6. quasar
Skill Challenge
1. the Big Bang 2. Visible light, electricity, and
magnetism formed. 3. about 1 second after the Big
Bang 4. the first atoms formed 5. 1 billion years
The Big Idea
Lesson Review
1. about 2 million light years 2. about 160,000 light
years 3. about 180,000 light years 4. Large
Magellanic Cloud Galaxy, Small Magellanic Cloud
Galaxy, Andromeda Galaxy
Skill Challenge
1. There is a direct and constant relationship
between a galaxy's speed, or velocity, and its
distance from Earth. 2. Andromeda Galaxy, Small
Magellanic Cloud Galaxy, Large Magellanic Cloud
Galaxy 3. The closer a galaxy is to Earth, the slower
it moves.
CHAPTER 18: THE SUN AND OTHER
STARS
Key Term Review
1. spectroscopy 2. magnitude 3. fusion
4. supernova 5. nebula 6. sunspot 7. galaxy
8. Big Bang 9. spectrum 10. white dwarfs 11. core
12. constellation 13. corona 14. supergiants
15. prominence
Topic: solar energy
Explanation: Solar energy is produced in the Sun by
nuclear reactions.