1. Energy sources Chapter 9

2. Energy cannot be created or destroyed according to the law of conservation of energy, but energy can be CONVERTED from one form to another

3. Types of energy sources

4. Energy Usage

5. FOSSIL FUELS Formed from decaying remains of ancient plants and animals Burning fuels convert energy from chemical bonds to heat and light. Chemical energy in fossil fuels is more concentrated that in other fuels

6. PETROLEUM Thick, greenish-brown highly flammable liquid formed by decaying ancient organisms -A process called fractional DISTILLATION separates the compounds in petroleum. - Petroleum is used for plastics, synthetic fabrics, and other products in addition to its use as a fuel.

7. Petroleum uses

8. NATURAL GAS Is also a product of decayed ancient organisms. It contains more energy per kilogram then petroleum or coal. It burns more cleanly then other fossil fuels. It provides about one fourth of the energy consumed in the United States.

9. How is natural gas used?

10. COAL A solid fossil fuel found underground. It produces more pollution when burned than petroleum or natural gas. It provides about one-fourth of the energy produced in the United States.

11. Uses of coal

12. Electricity is generated when fossil fuels are burned. The burned fuels release thermal energy. The thermal energy produces high pressure steam. The steam spins a turbine. The spinning turbine produces an electric current. The electric current is transmitted through power lines to consumers.

13. The cost of using fossil fuels

14. Only about 35% of the energy in fossil fuels reaches the consumers since some energy is lost in every stage of the process.

15. Fossil fuels have some undesirable side effects. Fossil fuels pollute the environment and increase carbon monoxide in the atmosphere. Mining coal can cause health problems for miners. Fossil fuels are NON-RENEWABLE resources so its important to not waste energy.

16. NUCLEAR ENERGY About 20% of the electricity in the U.S. comes from nuclear power plants. NUCLEAR REACTORS- contain a fuel, rods to control nuclear reactions, and a cooling system. Heat is produced by nuclear fission- energy is released when U-235 nuclei split in two after being struck by a neutron. Special rods absorb excess neutrons to prevent dangerous chain reactions.

17. Nuclear power plants use the heat of nuclear fission to produce steam. The steam drives a turbine. The turbine rotates on an electric generator.

18. Nuclear power plants produce NUCLEAR WASTE- radioactive by-products from radioactive materials. Low-level wastes contain only a small amount of radioactive material. High level wastes must be disposed of very carefully because they will remain radioactive for tens of thousands of years

19. Explain this cartoon.

20. Explain the importance of this cartoon.

21. Nuclear Fusion The joining together of nuclei- is not a practical energy source due to the high temperature fusion requires.

22. What risks do nuclear power plants pose?

24. Renewable energy sources- an energy source that is replaced nearly as quickly as it is used. Solar energy- Energy from the sun. A photovoltaic cell converts radiant energy into electrical energy.( also called solar cells) Hydropower- electricity produced through the movement of water. Wind power- use energy from the wind. Geothermal- converts energy from the ground into electrical energy. Biomass- organic matter being used to produce electricity. Foer example- wood, sugarcane fibers, rice hulls, and animal manure