2. MOLECULE: The smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms; a group of like or different atoms held together by chemical forces. ATOM: A part or particle considered to be an irreducible constituent of a specified system

13. Ozone O 3

22. Air pressure is greater near Earth's surface and decreases higher in the atmosphere . People find it difficult to breathe in high mountains because fewer molecules of air exist there .

23. Temperature in Atmospheric Layers Because some layers contain gases that easily absorb the Sun's energy while other layers do not, the various layers have different temperatures.

24. 20 C = 68 F cold ========================} hot

31. Ultraviolet radiation is one of the many types of energy that come to Earth from the Sun.

42. Earth’s Atmosphere is Unique On Earth, radiation from the Sun can be reflected into space, absorbed by the atmosphere, or absorbed by land and water. Once it is absorbed, heat can be transferred by radiation, conduction, or convection.

45. Heated Air Areas of Earth receive different amounts of radiation from the Sun because Earth is curved. The heated air at the equator is less dense, so it is displaced by denser, colder air, creating convection currents.

61. Multiple Choice 1. The ______ is the layer of the atmosphere nearest to Earth’s surface. A. mesosphere C. stratosphere B. troposphere D. ionosphere Answer B. troposphere

62. Multiple Choice 2. The ______ are windless zones near the equator. A. Doldrums C. Polar easterlies B. Prevailing westerlies D. Trade winds Answer A. Doldrums

63. Multiple Choice 3. In the water cycle evaporated water____. A. Precipitates as rain or snow C. Becomes groundwater B. Runs into lakes, streams, and oceans D. Condenses into clouds Answer D. Condenses into clouds

64. Multiple Choice 4. The ______ are responsible for the movement of much of the weather across the United States A. Prevailing westerlies C. Trade winds B. Polar westerlies D. Doldrums Answer A. Prevailing westerlies

65. Multiple Choice 5. The ______ merges into outer space. A. troposphere C. mesosphere B. stratosphere D. ionosphere Answer D. ionosphere

66. Multiple Choice 6. Air in the ______ is warmed by heat from Earth’s surface. A. troposphere C. stratosphere B. exosphere D. thermosphere Answer A. troposphere

67. Multiple Choice 7. Air above the ______ is heated more than at any other place on Earth. A. north pole C. equator B. south pole D. United States Answer C. equator

68. Multiple Choice 8. Air currents that blow near the north and south poles are the ______. A. Polar easterlies C. Polar westerlies B. Trade winds D. Jet streams Answer A. Polar easterlies

69. Multiple Choice 9. Reflection and absorption by the atmosphere prevent some ______from reaching Earth’s surface. A. ozone C. nitrogen B. radiation D. oxygen Answer B. radiation

70. Multiple Choice 10. Temperatures in the thermosphere are ______. A. Hot and cold C. Very cold B. Constantly changing D. Very warm Answer D. Very warm

71. Multiple Choice 11. ______is the only substance that exists as a solid, liquid, gas in Earth’s atmosphere. A. nitrogen C. water B. ozone D. radiation Answer C. water

73. Completion Complete each statement 17. The lowest layer of the atmosphere is the ___________ ; it contains clouds and smog. troposphere 18. An oxygen form present in the ___________ filters ultraviolet radiation from the sun. Ozone layer

74. Completion Complete each statement 19. Winds blowing from the northeast to the southwest near the north pole are known as _____________ . Polar easterlies 20. Air masses moving in the northern hemisphere are turned westward from their original paths in the _____________. Coriolis effect

75. Completion Complete each statement 21. Windless zone at Earth’s equator where air rises almost straight up is called the ________. doldrums 22. Cool dense air near the sea moves inland toward warm, dense areas during the day and sets up _________. Sea breeze

76. Completion Complete each statement 23. At 30 ° north or south of the equator air descending to Earth’s surface creates steady ___________. Trade winds 24. The __________________ blow from southwest to northeast at 30 ° to 60°latitude in the northern hemisphere . Prevailing westerlies

77. Completion Complete each statement 25. Cool , dense air moves during the night from the land toward water as __________ land breezes 26. Each hemisphere has two narrow belts of fast moving winds called__________ . Jet streams _

78. Completion Complete each statement 27. More harmful ultraviolet rays are reaching Earth’s surface because of ______________. Ozone depletion 28. Water pollution can be caused by pesticides and ________ used on farms. fertilizers

79. Completion Complete each statement 29. The ___ is the most reliable source of energy for life on Earth. Sun 30. A rise in Earth’s temperature possibly caused by an increase in greenhouse gases, is known as ______________ . Global warming

80. Completion Complete each statement 31. Sunlight _________. renewable

81. Short answer Describe each of the following concepts 32. The destruction of ozone by chlorofluorocarbons The chlorine atoms in CFC’s can break up ozone molecules and destroy ozone’s ability to absorb UV radiation answer

82. Short answer Describe each of the following concepts 33. The cause of the difference in temperature between the equator and the poles. Because Earth’s surface is curved not all areas receive the same amount of radiation from the Sun. The equator receives more direct radiation so its temperatures are higher. The poles receive less direct radiation so their temperatures are lower answer

83. Short answer Describe each of the following concepts: 34. The two most abundant gases in our atmosphere. Nitrogen and oxygen answer

84. Use the chart to answer the following questions: 35.Over which material did the air heat faster 36.Over which material did the air cool faster Answer sand Answer sand 27° C 28° C 25° C Above water 26° C 33° C 25° C Above sand Temperature after heat turned off for 15 minutes Temperature after heat applied for 15 minutes Original temperature reading thermometer

85. Short answer 37. How can the temperatures of sand and water affect the climate of the area? The differences in the heating and cooling of land and water affect the movement of warm air in the area. answer

86. Short answer 38. How does this information explain the differences between land and sea breezes? Land warms more easily than water. During the day, cooler, denser air from over water flows over the land and forces up the warm air; this is a sea breeze. Land cools more quickly than water. At night the air above land cools, sinks and moves out over water, forcing up the warmer air over the water. This is a land breeze. answer

87. Use the circle graph to answer the following questions. nitrogen oxygen Water vapor 0.0 to 4.0% 21% 78%

88. 39. Which gas makes up about one-fifth of Earth’s atmosphere? Answer oxygen 40. About what percent of Earth’s atmosphere does water make up? Answer 0 to 4% 41. How could you express the amount of nitrogen in Earth’s atmosphere as a fraction? Answer 3/4 to 4/5

90. 42. The following sentences appear in an events chain concept map that shows how CFC’s destroy the ozone layer. Number the sentences in the order in which they would appear on the map 3. The ozone molecule breaks apart 1. A regular two atom O2 molecule is formed 2. A chlorine atom from a chlorofluorocarbon molecule comes near a molecule of ozone

91. Think for yourself 43. Where is the air pressure the greatest, at sea level or on a mountaintop? Explain answer Air pressure is greatest at sea level because there are more molecules pushing down from above.

92. Think for yourself 44. Discuss some of the possible effects of global warming. answer Global warming could alter the amount of rainfall, affecting food production. Polar ice caps could melt, raising sea levels, and flooding coastal areas. The numbers and severity of storms and hurricanes also could.