What is a fossil? 1. Organisms die 2. Their remains were covered with sand, soil, and other sediments. 3. These sediments harden over and around the organism’s remains. A fossil is the remains or traces of a once- living organism in rock or soil. How are fossils formed?

3 Fossils give clues about organisms that lived long ago. They help to show that evolution has occurred. They also provide evidence about how Earth’s surface has changed over time. Fossils help scientists understand what past environments may have been like. What do fossils tell us?

4 Fossil Fuels A fossil fuel is a material that formed from the decay of ancient organisms and is used today as a source of energy. Example of fossil fuels are oil, gas, and coal,

5 How Coal is Formed 1. Plants or organisms die 2. Sediment or dirt build up on top of the organisms 3. Pressure from the layers of sediment pressed the organisms to form peat 4. The peat hardened and turned into sedimentary rock called Bituminous coal or soft coal. 5. The peat that was buried deeper was changed in metamorphic rock Anthracite coal or hard coal.

6 How oil and gas are formed 1. Decay organisms are buried deep under the ocean floor 1. Heat, weight of rock, and bacteria turn decayed organisms into oil and natural gas

7 How old are fossils and fossil fuels? Law of Superposition- each layer of rock is older than the layer above it Relative Age- is how old one rock is compared to another rock Absolute Age-the age of a fossil in years Era- is a unit of time measured in millions of years

8 Continued Geological Period- divides an era into a smaller amount of time 1. Paleozoic- age of ancient life (most ancient) 2. Mesozoic- age of reptiles (dinosaurs) 3. Cenozoic- age of dominant mammals

9 Alternate Energy Source Alternate Energy Source- any source of energy other than fossil fuels This includes wind, moving water, and solar energy or energy from the Sun

10 Energy from Wind A. Wind moves the blades on a wind mill B. Which turns gears and shafts to turn electric generators C. Parts of the generator move and produce electricity Positives: Doesn’t waste fossil fuels Doesn’t pollute the air Negatives: Need wind at all times Interferes with migrating birds

11 Energy from Moving Water Two things that are produced from moving water A) Grind Wheat 1. Running water or falling water turns a wheel that moves an axle 2. The axle moves two large stones 3. Grain is put between the stones and ground into powder

12 Energy from Moving Water Continued B) Producing Electricity 1. Falling or flowing water spins a generator 2. Which produces electricity Positives: does not pollute Negative:need moving water Effects animals that live in water

13 Solar Energy How are light and heat from the sun turned into energy? A. Solar cells turn sunlight that strike the solar cells into electricity B. Solar energy also heats homes using solar panels Positive: will not run out Negatives: does not pollute needs areas that are cloud free

14 Nuclear Energy A. Atoms of one element change into atoms of other elements B. The change occurs in the nucleus, or the center of them atom C. When the change occurs great energy is given off. D. This energy is called nuclear energy. E. The heat from the element change makes steam. F. The steam moves parts of an electric generator providing electricity.

Positives: does not pollute the environment less expensive than electricity made by burning fossil fuels Negatives: accidents can occur that pollute the air with radioactive material Nuclear Energy Contd

Geothermal Energy- energy that is produced from inside the earth A. causes hot springs and volcanoes B. steam from hot springs can be piped to machines C. The machines spin generators D. The generators produce electricity Negatives: have to be tapped from underground Only a few places on earth are located where this kind of energy is easy to reach. Geothermal Energy

Biomass- made up of materials from living things A. wood B. animal waster C. plant material (ex: corn) Positive: tree and crops are renewable resources Negatives: Does not release as much energy as burning fossil fuels. Growing plants for fuel decreases the amount of land available for crops. Biomass

1. Turn off lights and electronic equipment. 2. Limit your use of hot water. 3.Carpool 4. Turn your heat and air conditioner down. Conserve Energy

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