1. Chapter 2 Section 2 Review Page 38 Energy in the Earth System

2. 1. Explain how Earth can be considered a system.
Earth consists of many interacting components.

3. 2. Compare an open system with a closed system.
In an open system, matter and energy are added and removed.
In a closed system, only energy enters or leaves.

4. 3. List two characteristic of each of Earth’s four major spheres.
Atmosphere: contain gases needed for life and shields us from harmful radiation
Hydrosphere: covers 70% of Earth and contains all water that is not a gas
Geosphere: made up of rock and soil of crust and molten rock beneath surface
Biosphere: contains all living organisms and extends from the bottom of the oceans to the atmosphere

5. 4. Identify two main sources of energy in Earth’s system.
The Sun
Earth’s interior

6. 5. Identify four processes in which matter and energy cycle on Earth.
Chemical reactions
Radioactive Decay
Radiation of heat and light
Growth and decay of organisms

7. 6. Explain how carbon cycles in Earth’s system.
Carbon dioxide is absorbed by plants from the atmosphere. Plants make sugars and food substances from it. Animals eat plants to get it and both animals and plants release it to the atmosphere through respiration and their own decay.

8. Carbon Cycle

9. 7. Explain how nitrogen cycles in Earth’s system.
Nitrogen from the atmosphere is “fixed” by bacteria in the soil. Plants get the nitrogen from the soil and animals get the nitrogen from eating plants. Plants, animals, and bacteria release the nitrogen back to the atmosphere through excretions or decomposition.

10. Nitrogen Cycle

11. 8. Describe how the water cycle affects each of the four spheres.
1. Water evaporates into the atmosphere and moderates the temperature of air.
2. Water precipitates onto the geosphere and causes weathering and erosion of rock.
3. Water in the biosphere sustains life.
4. Water as precipitation in the hydrosphere replenishes supplies of fresh water.

12. 9. What effect would a massive forest fire have on the amount of carbon dioxide in the atmosphere.
It would add carbon dioxide to the atmosphere because when organisms like trees burn they release carbon dioxide.
Yellowstone Fire, 1987

13. 10. Early Earth was being constantly bombarded by objects from space
10. Early Earth was being constantly bombarded by objects from space. Was early Earth and open system or a closed system?
Early Earth was an open system because matter and energy were being added to it.

14. 11. Explain the role of energy in the carbon cycle.
As carbon moves through the carbon cycle, it undergoes chemical and physical changes that involve transfers of energy.

15. The End…