Final Flashcards

0
Q

Is energy releases by the fission process?

A

Yes, the separated fragments are more stable energetically than the original heavy nucleus, energy is released by the process

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1
Q

Define fission

A

The collision of heavy nuclei (which all have many neutrons and protons) with a neutron that results in the splitting of the nucleus into two similarly sized fragments.

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2
Q

235 U fissioned reaction?

A

1/0 n + 235/92 U –> 142/56 Ba + 91/36 Kr + 3 1/0 n

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3
Q

Function of the moderator?

A

To slow down the neutrons that are moving to fast to be efficiently absorbed by other nuclei and cause further fission so they can be useful.

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4
Q

What can the moderator contain?

A

Regular water, heavy water, or graphite.

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5
Q

What is the function of the coolant?

A

Used to carry off the heat energy produced by the fission.

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6
Q

What is the coolant material?

A

Water or carbon dioxide

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7
Q

Why are “spent” fuel rods more radio active than the original fuel?

A

Because the nucleus fissions and the by product are highly radio active. As a consequence the spent fuel rods are more radio active than the original uranium.

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8
Q

238 U reaction in a fission reactor?

A

1/0 n + 238/92 U –> 239/92 U –> beta + 239/93 Np –> beta + 239/94 Pu

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9
Q

Why does the mining of uranium pollute the local environment?

A

Because the contamination of radioactive substances commonly occurs, uranium slowly decays into other substances that are also radio active, uranium ore also contains a variety of radio active elements. So large volumes of waste material that remains after the uranium is chemically extracted from the ore itself is radio active

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10
Q

What is a breed reactor?

A

Nuclear power reactors that are designed specifically to maximize the production of by product plutonium

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11
Q

Why is it useful to breed fissionable fuel?

A

So you can dispose of excess plutonium and the fuels can be used in nuclear reactors

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12
Q

Define fusion?

A

The combination of two very light nuclei to form one combined nucleus

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13
Q

Does fusion result in high amount of energy?

A

Yes, the combined nucleus is more stable than the original light ones.

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14
Q

Two examples of fusion?

A

Energy in the stars, and hydrogen bombs

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15
Q

Advantages on solar energy?

A

Free and abundant
Low environmental impacts
Low operating cost
High public acceptance

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16
Q

Disadvantage on solar energy?

A

Intermittent
Diffusion
High capital cost
No economic tax or regulatory credit

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17
Q

Pros of wind power?

A
Sites remote of dense populations can be used
Noise level comparable to traffic
Can be stored mechanically
Very little green house gas emissions
Conventional
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18
Q

Cons of wind power?

A

Far from centres of demand so long transmission lines needed
Tax incentives needed
Require additional infrastructure
Kill wildlife
Noise pollution
Visual pollution
Intermittent so requires back up resources for power.

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19
Q

Cellulostic ethanol?

A

Cheaper source of energy created by woody plants that contain cellulose, hemicellulose and lignin.

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20
Q

What is an energy source

A

Material consumed in the generation of power

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21
Q

What is an energy carrier?

A

responsible for sending, receiving and transporting energy. Must be produced.

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22
Q

Is hydrogen an energy carrier or source?

A

Carrier

23
Q

How do hydrogen fuel cells work?

A

Two gases are passed over separate electrodes that are connected by an external electrical connection through which electrons travel and also through an electrolyte which through ions travel.

24
Q

How does the total available supply of solar energy compare to our current commercial energy needs?

A

The sun send out 10 000 times more our conceivable energy requirements

25
Q

List the renewable energy sources?

A

Biomass, geothermal, wind, solar, hydro

26
Q

What percentage of our global commercial energy is currently obtained from renewables ?

A

13%

27
Q

Which of the renewable energy sources have their origins in solar energy and what is the percent of commercial energy currently supplied by solar energy?

A

All except geothermal. And 0.53%

28
Q

Globally, is renewable energy use increasing or decreasing, and which of these renewables is decreasing the fastest?

A

Decreasing and biomass

29
Q

What is the potential for growth worldwide in hydro electric power?

A

Could produce 80% of the worlds renewable energy

30
Q

What is the potential for expansion for those countries most suited to wind power?

A

Rising about 25% per year

31
Q

Define energy payback?

A

The amount of time required to generate the energy used in constructing the unit

32
Q

state which form of renewable energy has the lowest payback period and the lowest cost at present.

A

Wind power

33
Q

How does wind power compare with other sources in terms of a) Energy payback? b) CO2 emissions c) How economical it is

A

High energy pay back, low carbon emissions, high economical stance.

34
Q

By what two mechanisms can sunlight be converted to electricity?

A

Thermal conversion and photo conversion

35
Q

Describe the difference between the two methods of absorbing energy from sunlight.

A

Thermal conversion - sunlight is captured as heat by some absorbing material
Photo conversion - absorption of photons associated with the ultra violet, visible, infrared components of sunlight bring excitement to higher energy levels of electrons in the absorbing material.

36
Q

What are active and passive solar systems?

A

Passive - systems that do not require an additional energy source to operate them.
Active - employ additional energy source to operate them

37
Q

Why are solar cells the most CO2 intense renewable energy source?

A

Although the solar cells do not generate any carbon emissions, their manufacturer does consume a significant amount of energy and there fore cause substantial carbon emissions

38
Q

What is meant by the symbol E10?

A

10% ethanol mixture

39
Q

What are advantages and disadvantages of oxygenated fuels (fuels containing alcohols for example)?

A

Lower CO, alkenes, aromatics, and particulates emissions

Acetaldehyde emissions increase
Low vapour pressure

40
Q

Could bio fuels replace oil as a source of transportation fuels? Explain.

A

Yes because corn and and sugarcane are being used to produce bio ethanol. Many farmers in the U.S and Canada are in support of its production for the use of ethanol in gasoline. Making it economically competitive with petroleum. Could not replace petroleum worldwide.

41
Q

What is syn gas?

A

Mixture of CO and H2

42
Q

Write the reactions showing the production of syn gas from both methane and coal.

A

C + H2O –> CO + H2

CH4 + H2O –> CO + H2

43
Q

Write the reaction showing the production of syn gas from H2

(generated perhaps from solar or wind sources).

A

CO2 + H2 —> CO + H2O

44
Q

Write the reversible reaction showing the production of methanol from syn gas, and then show why the water gas shift reaction is needed to make methanol from either fossil fuels, or from H2.

A

CH3OH –> H2 + CO

45
Q

Why is it an advantage to be able to convert methane, coal, biomass, and hydrogen gas into methanol?

A

High octane fuel, vaporizes less rapidly, vapour disperses more quickly, burns more cleanly than gasoline

46
Q

What would be the advantage of converting methane, coal, biomass, hydrogen gas and methanol into gasoline?

A

Can be produced from either. Less emissions?

47
Q

What are some advantages and disadvantages of MTBE?

A

Higher octane number, does not evaporate as readily,

Combustion produces more aldehydes and other oxygen containing pollutants

48
Q

What has been the effect of palm tree plantations on the cradle to grave production of CO2 from biodiesel?

A

Large amount of carbon emissions

49
Q

What pollutants are produced first in the production, and then in the combustion of hydrogen?

A

Nox and H2O2

50
Q

What is considered to be the boundary separating the dangerous consequences of emissions from the merely unwise?

A

Doubling the amount of CO2

51
Q

Energy reserve?

A

Actual known deposits which are obtainable at some fixed market price

52
Q

Energy source?

A

Entire known amount of a resource

53
Q

Ultimate origin of coal, oil and gas?

A

Dead living things

54
Q

Greatest reserve abundance?

A

Gas hydrates, coal, natural gas, and oil