6.6 Energy of the Atom

Question 1

Nuclear reaction

Answer 1

Chemical reactions that occur in the nuclei of an atom

Question 2

Nuclear fission

Answer 2

When the nuclei of larger atoms such as Uranium-235 splits into smaller nuclei and release huge amounts of energy as heat and gamma radiation

Question 3

Explain how a chain reaction may occur for fission of Uranium-235

Answer 3

When a slow neutron collides with U-235 nuclei, this initiates a reaction, creating fission products of Barium and Krypton, as well as energy and fast neutrons. When these fast neutrons slow down, they may collide with another U-235 nucleus and initiates a chain reaction.

Question 4

Cold fusion

Answer 4

Fusion can only in high temperatures and scientists are investigating ways to conduct fusion reactions in lower temperatures to harvest its energy.

Question 5

Explain the process of fission in a nuclear power station

Answer 5

When fission occurs in the core, control is used to either slow or increase the rate of reactions by absorbing or slowing down neutrons. When lowered, the control rods absorb neutrons and decreases the rate of reactions. When raised, neutrons are free to collide with U-235 and the rate of reaction increases.

The thermal energy produced heats the water and forms steams, which is channelled out of the containment vessel and turns the turbine, rotating an electrical generator and producing electricity.

Question 6

3 arguments for nuclear energy

Answer 6

1. Very energy efficient
2. Australia is plentiful of Uranium
3. Environmentally friendly compared to traditional fuels

Question 7

3 arguments against nuclear energy

Answer 7

1. Expensive due to construction and safety precautions
2. Dangerous due to historical examples
3. Nuclear waste management is unsatisfactory with current methods of steel/concrete containers or vitrification. Risks of leakage and environmental damage.