Skills Worksheet Chapter Review USING KEY TERMS For each pair of terms, explain how the meanings of the terms differ. 1. terrestrial planet and gas giant 2. asteroid and comet 3. meteor and meteorite Complete each of the following sentences by choosing the correct term from the word bank. astronomical unit meteorite meteoroid prograde retrograde satellite 4. The average distance between the sun and Earth is 1. 5. A small rock in space is called a(n). 6. When viewed from above its north pole, a body that moves in a counterclockwise direction is said to have rotation. 7. A(n) is a natural or artificial body that revolves around a planet. UNDERSTANDING KEY IDEAS Multiple Choice 8. Of the following, which is the largest body? a. the moon c. Mercury b. Pluto d. Ganymede Holt Science and Technology 62 A Family of Planets
9. Which of the following planets have retrograde rotation? a. the terrestrial planets b. the gas giants c. Mercury and Venus d. Venus and Uranus 10. Which of the following planets does NOT have any moons? a. Mercury b. Mars c. Uranus d. None of the above 11. Why can liquid water NOT exist on the surface of Mars? a. The temperature is too high. b. Liquid water once existed there. c. The gravity of Mars is too weak. d. The atmospheric pressure is too low. Short Answer 12. List the names of the planets in the order the planets orbit the sun. 13. Describe three ways in which the inner planets are different from the outer planets. 14. What are the gas giants? How are the gas giants different from the terrestrial planets? 15. What is the difference between asteroids and meteoroids? Holt Science and Technology 63 A Family of Planets
16. What is the difference between a planet s period of rotation and period of revolution? 17. What gases are the major components of Uranus and Neptune? 18. Which characteristics of Earth make it suitable for life? 19. Why do scientists think that Miranda, a moon of Uranus, was once broken apart by a collision with another large body? 20. What two bodies in the solar system have been reclassified as dwarf planets? Holt Science and Technology 64 A Family of Planets
CRITICAL THINKING 21. Concept Mapping Use the following terms to create a concept map: solar system, terrestrial planets, gas giants, moons, comets, asteroids, and meteoroids. Holt Science and Technology 65 A Family of Planets
22. Applying Concepts Even though we haven t yet retrieved any rock samples from Mercury s surface for radiometric dating, scientists know that the surface of Mercury is much older than that of Earth. How do scientists know this? 23. Making Inferences Where in the solar system might scientists search for life, and why? 24. Making Inferences Jupiter s moon Io is the most volcanically active body in the solar system. What might you infer about the surface of Io? 25. Predicting Consequences If scientists could somehow bring Europa as close to the sun as the Earth is, 1 AU, how do you think Europa would be affected? 26. Identifying Relationships How did variations in the orbit of Uranus help scientists discover Neptune? Holt Science and Technology 66 A Family of Planets
INTERPRETING GRAPHICS The graph below shows density versus mass for Earth, Uranus, and Neptune. Mass is given in Earth masses the mass of Earth is equal to 1 Earth mass. The relative volumes for the planets are shown by the size of each circle. Use the graph below to answer the questions that follow. 27. Which planet is denser, Uranus or Neptune? How can you tell? 28. You can see that although Earth has the smallest mass, it has the highest density of the three planets. How can Earth be the densest of the three when Uranus and Neptune have so much more mass than Earth does? Holt Science and Technology 67 A Family of Planets