Chapter 2 Chapter 2 Section 2 Review Page 38Section 2 Review Page 38

Energy in the Earth SystemEnergy in the Earth System

1. Explain how Earth 1. Explain how Earth can be considered a can be considered a

system.system.• Earth consists of many Earth consists of many

interacting components.interacting components.

2. Compare an open 2. Compare an open system with a closed system with a closed system.system.

• In an open system, matter and In an open system, matter and energy are added and removed.energy are added and removed.

• In a closed system, only energy In a closed system, only energy enters or leaves.enters or leaves.

3. List two characteristic 3. List two characteristic of each of Earth’s four of each of Earth’s four major spheres.major spheres.

• Atmosphere: contain gases needed for Atmosphere: contain gases needed for life and shields us from harmful life and shields us from harmful radiationradiation

• Hydrosphere: covers 70% of Earth and Hydrosphere: covers 70% of Earth and contains all water that is not a gascontains all water that is not a gas

• Geosphere: made up of rock and soil of Geosphere: made up of rock and soil of crust and molten rock beneath surfacecrust and molten rock beneath surface

• Biosphere: contains all living organisms Biosphere: contains all living organisms and extends from the bottom of the and extends from the bottom of the oceans to the atmosphereoceans to the atmosphere

4. Identify two main 4. Identify two main sources of energy in sources of energy in Earth’s system.Earth’s system.

• The Sun The Sun

• Earth’s interiorEarth’s interior

5. Identify four 5. Identify four processes in which processes in which matter and energy cycle matter and energy cycle on Earth.on Earth.

•Chemical reactionsChemical reactions

•Radioactive DecayRadioactive Decay

•Radiation of heat and lightRadiation of heat and light

•Growth and decay of Growth and decay of organismsorganisms

6. 6. Explain how carbon cycles Explain how carbon cycles in Earth’s system.in Earth’s system.

• Carbon dioxide is absorbed by Carbon dioxide is absorbed by plants from the atmosphere. plants from the atmosphere. Plants make sugars and food Plants make sugars and food substances from it. Animals eat substances from it. Animals eat plants to get it and both animals plants to get it and both animals and plants release it to the and plants release it to the atmosphere through respiration atmosphere through respiration and their own decay.and their own decay.

Carbon CycleCarbon Cycle

7. 7. Explain how nitrogen Explain how nitrogen cycles in Earth’s system.cycles in Earth’s system.

• Nitrogen from the atmosphere is Nitrogen from the atmosphere is “fixed” by bacteria in the soil. “fixed” by bacteria in the soil. Plants get the nitrogen from the Plants get the nitrogen from the soil and animals get the nitrogen soil and animals get the nitrogen from eating plants. Plants, from eating plants. Plants, animals, and bacteria release the animals, and bacteria release the nitrogen back to the atmosphere nitrogen back to the atmosphere through excretions or through excretions or decomposition. decomposition.

Nitrogen CycleNitrogen Cycle

8. 8. Describe how the water cycle Describe how the water cycle

affects each of the four spheresaffects each of the four spheres..• 1. Water evaporates into the atmosphere 1. Water evaporates into the atmosphere

and moderates the temperature of air.and moderates the temperature of air.

• 2. Water precipitates onto the geosphere 2. Water precipitates onto the geosphere and causes weathering and erosion of and causes weathering and erosion of rock.rock.

• 3. Water in the biosphere sustains life.3. Water in the biosphere sustains life.

• 4. Water as precipitation in the 4. Water as precipitation in the hydrosphere replenishes supplies of fresh hydrosphere replenishes supplies of fresh water.water.

9. 9. What effect would a massive forest What effect would a massive forest fire have on the amount of carbon fire have on the amount of carbon dioxide in the atmosphere.dioxide in the atmosphere.

• It would add carbon dioxide to the It would add carbon dioxide to the atmosphere because when atmosphere because when organisms like trees burn they organisms like trees burn they release carbon dioxide.release carbon dioxide.

Yellowstone Fire, 1987

10. Early Earth was being constantly 10. Early Earth was being constantly bombarded by objects from space. bombarded by objects from space. Was early Earth and open system or a Was early Earth and open system or a closed system? closed system? • Early Earth was an open system Early Earth was an open system

because matter and energy were because matter and energy were being added to it.being added to it.

11. Explain the role of energy in 11. Explain the role of energy in the carbon cycle.the carbon cycle.

• As carbon moves through the carbon As carbon moves through the carbon cycle, it undergoes chemical and physical cycle, it undergoes chemical and physical changes that involve transfers of energy.changes that involve transfers of energy.

The End…The End…