Page 200 - Science Course 3 (Book 2)

Mo13-L1: Vocabulary Review

Direction: On each line, write the term from the word bank that correctly replaces the underlined words
in each sentence. Use each term only once. NOTE: You may need to change a term to its
plural form

asteroid astronomical unit comet orbit
period of revolution period of rotation star

1. Many objects, including planets, travel around the Sun.

2. Orbiting objects made of gas, dust, and ice come from the outer parts of the
solar system.

3. The Sun is a(n) structure in space made of gases in which nuclear fusion
reactions occur.

4. In 365 days, Earth completes a(n) full journey around the Sun.

5. In 24 hours Earth completes a(n) full turn, also called a complete spin.

6. Millions of small, rocky objects orbit the Sun between the orbits of Mars and
Jupiter.

7. A(n) distance equal of about 150 million km is the average distance from
Earth to the Sun

Mo13-L1: Key Concept Organizer

Direction: On the line before each description, write the letter of the term that matches it correctly.
Some terms will be used more than once.

A. Sun
1. four planets closest to the Sun
B. inner planets
2. nonspherical rocky objects
C. asteroids
3. the largest object in the solar system
D. outer planets
4. Jupiter, Saturn, Uranus, and Neptune
E. dwarf planets
5. one trillion of them might orbit the Sun
F. comets
6. a source of light energy
7. planets made of mostly solid rocky materials

8. Ceres, Pluto, Eris, and Makemake
9. planets made mainly of ice and gases

10. Mercury, Venus, Earth, and Mars
11. sometimes called gas giants

12. where nuclear fusion reactions occur
13. planets much larger than Earth

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