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Office buildings are part of the
commercial sector.
In 1875, the principal energy source in the United States was
wood
Which one of the following statements about energy transitions is correct?
The United States has switched from wood to coal.
The energy content of a fuel is the
amount of energy in a kilogram of fuel
The cheapest way to mine coal is
surface mining.
Which fuel burns cleanest?
natural gas
Which of the following is not a renewable resource used by early humans?
Burned Kerosene
Which of the following is a brownish-black organic material that is used to build up garden soil?
peat
Until 1979, total U.S. energy demand was
increasing exponentially
Even though the products of coal combustion make coal look like a poor fuel, why are we returning to coal as a significant source of energy? (3 reasons)
We have a lot of coal.
We are running out of petroleum.
Coal decreases our need for foreign oil.
At the present time, which one of the following provides the greatest amount of energy for powering the U.S. economy?
Oil
Oil is very plentiful and domestic supplies should last for centuries.
True or False
FALSE
Why is surface mining a problem? (3 reasons)
Irrigation is needed to reclaim the land.
It removes good topsoil from productive use.
It creates erosional problems.
How has underground mining improved? (3 Ways - Name at least 2)
It is safer.
We have achieved greater production with machines.
The percentage recovery has increased.
Of all the energy sources we presently rely on, this source has, by far, the largest reserves for future use.
coal
A type of low-grade coal that is only 70% carbon would be
Lignite
Because of its wide availability around the country and its energy content, this type of coal is most often burned at electric power generation plants in the United States
Bituminous
Which of the following types of coal is found mostly in eastern Pennsylvania?
anthracite
Steam electric generating plants always produce a certain amount of
thermal pollution
The practice of dumping waste heat into nearby lakes, rivers, or bays results in
death and destruction to ecosystems.
This includes all of the following:
increased metabolic rates in fish, dissolved oxygen loss, thermal pollution, and lowered populations of desirable fish.
This type of coal is very hard, high grade, and has a very high carbon content
anthracite
Which of the following is a very low-grade coal that is rich in volatiles and is good feedstock for coal gasification?
Lignite
Which of the following is a high-grade coal that is hard to ignite, but once lit burns with almost no smoke?
anthracite
If coal is ranked in terms of its energy (content) density from lowest to highest, the correct sequence is
peat, lignite, bituminous, anthracite.
At an electric power plant, electricity is produced in the
generator