Physical Science 8th grade (1).pdf

14 if a meterologist describes the air as saturated

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14. If a meterologist describes the air as saturated, what does he or she mean? 15. Give one example of natural convection. 16. What type of heat transfer is represented in the diagram below? 17. From where does the carbon in a tree come from? 18. What two gases make up the majority of the atmosphere? 19. How does rain form? Section 5.2 20. Why can solid materials hold their shape? 21. How does glass behave differently when it is solid versus when it is heated? Why? 22. What crystal forms the basis for much of the microelectronics industry? What makes it so valuable? 23. What physical properties make plastics such a valuable material for manufacturing goods?
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115 C HAPTER 5 S TATES OF M ATTER C HAPTER 5 A SSESSMENT 24. Describe an example using the terms conduction and thermal equilibrium . Identify each of the following as a thermal conductor or insulator: a. copper pipe b. styrofoam cup c. wooden spoon d. a vacuum space e. aluminum pot Problems Section 5.1 1. According to the diagram, most of our weather occurs below what altitude? 2. The air in your school can hold 20 g/m 3 of water when it is saturated at 70°F. What is the relative humidity of the air in your school at 70°F if the moisture content is 5 g/m 3 ? 3. The diagram to the right shows a graph of temperature vs. time for a material which starts as a solid. Heat is added at a constant rate. Using the diagram, answer the following questions: a. During which time interval does the solid melt? b. During which time interval is the material all liquid? c. What is the boiling point of the substance? d. Does it take more heat energy to melt the solid or boil the liquid? Section 5.2 4. Based on the definition of a vacuum, if you were to put an alarm clock inside a vacuum and set it to ring, what would happen when the alarm went off? 5. The diagram shows a cup of cocoa at 65°C. The arrows show the direction of heat conduction as a cold spoon is placed into the cup. What could the temperature of the spoon be? a. 75°C b. 65°C c. 55°C 6. Which make the best thermal conductor: solids, liquids, or gases? Why?
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THIS AT HOME Atoms and the Periodic Table Chapter 6 The Atom Chapter 7 Elements and the Periodic Table Chapter 8 Molecules and Compounds Matter contains positive and negative charges. Put a small handful of puffed cereal or puffed rice into a saucer. Inflate and tie a balloon. Rub the balloon back and forth on your hair, a sweater, or a sock a dozen times. Hold the balloon near the cereal. What happens? Try this with another kind of puffed cereal and compare to the first. Write a paragraph about your observations.
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