What is fuel?
• A fuel is a substance that provides a form of energy.
• Energy can be in the form of heat, light, electricity, or motion.
• When fuel is burned it releases energy: this is called combustion.
Fossil fuels
• What is a fossil?• Fossil fuels are the energy-rich substances
formed from the remains of once living organisms.
Three Fossil Fuels:
CoalOil (petroleum)Natural Gas
Nonrenewable resources• Fossil fuels are non-renewable – they are being
used up faster than they are made.• They take a long time to form and could run out.
– What are the three fossil fuels?CoalOilNatural Gas
Quick Review!
Alternative Energy Resources
We need to find alternative energy resources so that we do not use up all of our nonrenewable
resources
Renewable Resources• A renewable resource is constantly being
supplied.• What are some renewable resources?
Solar Energy1. Solar energy – light and heat energy from the
sun2. Solar energy is the source for wind and water
energy.– How?
• Wind – unequal heating of the Earth causes global winds
• Water – sun heats water for evaporation to start the water cycle
Wind1. Can be used to cause turbines to
move and generate electricity2. The least reliable because of
weather
Hydroelectric Power
1. Flowing water causes the turbines to move and generate electricity.
2. The most common and most used.
Biomass fuels1. Biomass fuels are made from organic
materials.Examples include:– Wood– Leaves– Food wastes– Manure
Protect our Resources
• You have two minutes. Brainstorm some ways we can conserve our nonrenewable resources.
Energy Conservation
• Conservation means to save energy.• Two ways to avoid fuel shortage:1. Find new sources of energy2. Make fuels available last as long as possible
Ways to conserve:
• Walk or ride bike instead of drive• Put on sweater instead of turning on heat• Use fans instead of air conditioning• Use sunlight instead of electric lights• Turn off lights or TV when you leave the room• Recycle!
Water Pollution
• How would you feel if you turned on your water faucet and a stream of nice, fresh, bright green water came out?
• Many things can make water unsafe to drink but don’t change its color, taste, or smell.
• Water pollution is anything that has a harmful affect on the water or the living things in the water
Water Pollution
• What types of water can be polluted?– Surface water– Ground water– Even rain!
• Pollution can result from natural causes and human activities
Sources of Water Pollution
• The major sources of water pollution are human wastes, industrial wastes, agricultural chemicals, and runoff from roads.
Water Pollutants
Disease causing
organisms
Pesticides and
fertilizers
Industrial Chemicals
MetalsRadioactive
wastes
Medical and scientific
Disposal sites, Nuclear
power plants
Petroleum products
Human wastes
and Runoff from
livestock pens
Runoff from farms
and golf courses
Factories
Factories, waste
disposal sites
Road runoff, leaking
Underground storagetanks
Human Wastes
• Human wastes can carry bacteria that causes diseases
• Sewage can leak wastes into drinking water• Wastes can also come from farm animals• If you boil water it kills many disease causing
organisms
Industrial Wastes
• Some factories release toxic chemicals into nearby rivers and lakes
• Many power plants, factories, and cars pollute the air – it then falls as acid rain
• Pouring hot water into lakes and rivers can kill living organisms
Water Pollution:
• Agricultural Chemicals– Runoff from farms can carry fertilizers and
pesticides that pollute water
• Runoff from Roads– Oil, gasoline, and salt from cars can runoff the
road to pollute rivers and lakes
Soil Pollution
• Soil can become polluted by– Landfills– People burying hazardous wastes– Polluted ground water
Air Pollution
• Some air pollution is natural (volcanoes, animals), but most is caused by humans
• Factories, cars, and power plants release toxins into the air which create smog and acid rain.
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