Chapter 8&9

Question 1

What are some negatives towards wind power?

Answer 1

1. Changes climate and wind speed
2. Harms bird and bird migration
3. Humans have side effects

Question 2

How does wind power work?

Answer 2

Wind it’s the rotor which turns the gear box that generates power through the motor

Question 3

How do solar and thermal energy work?

Answer 3

Heating of water or other energy carrier by concentrated solar heat
- needs really sunny areas

Question 4

What are solar photovoltaics?

Answer 4

Converting solar energy into electricity with a semi conductor material that absorbs sunlight, which causes the formation of electron-hole pairs
- pairs are separated producing an electric current

Question 5

Why are sola and wind energy limiting?

Answer 5

Sun is only available during the day

Wind is only good when the days are windy

Question 6

What is radioactivity?

Answer 6

The spontaneous emission of radiation

Question 7

What does radiation include?

Answer 7

Alpha particles : nucleus of atom
Beta : fast moving electrons
Gamma rays : carry a lot of energy and move quickly

Question 8

How are alpha particles created?

Answer 8

Artificially made by ejecting from the nucleus of a larger atom

Question 9

How are beta particles formed?

Answer 9

Formed when a neutron splits into a proton and an electron in the nucleus

Question 10

What are gamma particles?

Answer 10

Photons that are high in energy

Question 11

What is ionizing radiation?

Answer 11

When energy is absorbed it can ionize molecules

When living things absorb it, it can damage the molecules or ionize them

Question 12

Which is more dangerous; alpha beta or gamma?

Answer 12

Gamma is more dangerous because it can penetrate the the skin easily
- a and b are only dangerous if if emitted when radioactive species is ingested

Question 13

What is the rate of decomposition expressed as?

Answer 13

Half life

Question 14

What is nuclear fission?

Answer 14

Splitting of a heavy atom into a lighter one

- large amounts of energy produced

Question 15

How is nuclear fission initiated?

Answer 15

When neutrons are shot at the nucleus of an atom

Question 16

What is the most common atom used?

Answer 16

235 Uranium

-nuclei have kinetic energy, evolves into heat

Question 17

What do the neutrons go on to do?

Answer 17

They can initiate another fission reaction (chain reaction)

Question 18

Where does the energy come from a nuclear reaction?

Answer 18

When the heavy nucleus is converted to s lighter nuclei some energy is released

Question 19

What are the components of the energy released during s fission reaction?

Answer 19

Gamma rays and other kinds of radiation

Question 20

How is the nuclear energy absorbed ?

Answer 20

It is absorbed by the coolant

Question 21

Why is heating of the coolant important?

Answer 21

It generates steam which turns the turbine to produce energy

Question 22

Why do we use uranium for nuclear reactions?

Answer 22

The isotope is fissile

Question 23

What does it mean when an isotope is fissile?

Answer 23

It can sustains fission chain reaction

- each fission can trigger one or more further acts of fission

Question 24

What are nuclear reactions controlled by?

Answer 24

It slows the reactions and controls the rods that absorb neutrons

Question 25

What happens when the reaction gets out of control?

Answer 25

The reactors can have a meltdown

- core is melted due to the accumulated heat

Question 26

Plans for nuclear waste?

Answer 26

For highly radioactive material underground in non-corrosive metal containers
For low radioactive material in a giant warehouses in the same containers with reinforced walls

Question 27

What is nuclear fusion?

Answer 27

Joining light atoms to produce heavier atoms

Question 28

Pros of fusion nuclear energy?

Answer 28

1. No long term pollution
2. Cleaner than fission energy
3. Produces tons of energy at high temps ( current tech can’t handle that)

Question 29

What are 4 pros of fission nuclear energy?

Answer 29

1. Produces a lot of energy
2. No polluting
3. Doesn’t contribute to global warming or acid rain
4. Stable source of energy ( unlike solar)

Question 30

What are cons of nuclear fission?

Answer 30

1. Expensive precautions for safety
2. Fission products are radioactive
3. Not 100% true renewable ( fossil fuels use to extract and transport uranium)

Question 31

What are some negatives towards hydroelectric?

Answer 31

1. Flooding large area of land
2. Fish migration
3. Displacing human and animal populations