Fossil fuels such as coal, oil, and natural gas are nonrenewable resources that were formed from the remains of ancient plants and animals. They provide most of the energy for electricity generation in the United States, especially coal which is the cheapest to use. However, burning fossil fuels causes air, water, and soil pollution and increases carbon dioxide emissions. While fossil fuels take millions of years to form, once depleted they cannot be renewed on a human timescale.
5. 27) Most electricity in the U.S.A. is
generated by coal burning power
plants because it is the cheapest to
use and produces large amounts of
energy.
6. 28) The three types of fossil fuels
are coal, oil, and natural gas.
7. 29) Fossil fuels are the most
commonly used nonrenewable
resources.
9. 31) The sun provides energy to
plants and the plants use
photosynthesis to help them grow.
10. 32) The ultimate source of the energy in
fossil fuels is from the sun.
Photosynthetic plants and marine algae
lock this energy into organic matter.
When we burn plants, coal, oil, or gas,
we release the sun's trapped energy.
14. 36) Coal is an organic rock that
originally came from dead swamp
grass that compacted over millions
of years.
15. 37) The fossil fuel coal formed from
the remains of plants that lived and
died around 100 to 400 million years
ago, when parts of the earth were
covered with huge swampy forests.
16. 38) Coal is considered a
nonrenewable energy source
because it takes millions of years to
form.
17. 39) Of the fossil fuels, natural gas
produces the least amount of
pollution.
18. 40) Natural gas is a naturally
occurring hydrocarbon gas mixture
consisting primarily of methane, with
other hydrocarbons, carbon dioxide,
nitrogen and hydrogen sulfide.
19. 41) Natural gas is an energy source
often used for heating, cooking, and
electricity generation.
20. 42) Petroleum oil is a nonrenewable
fossil fuel usually found
underground in reservoirs located in
sandstone or limestone. This fossil
fuel is made from sea plants and
animals.
21. 43) The energy source used more
than any other in the U.S.A. is oil.
