What is nuclear fission?
The splitting of an atom
The joining of two light nuclei
The splitting of a heavy nucleus
What is a chain reaction?
A reaction that causes a chain made from uranium to split
When atoms of uranium join together in a long chain
When neutrons from one reaction fire off to cause further reactions
What particle is used to trigger the fission of a uranium nucleus?
A neutron
A proton
An electron
How is the chain reaction slowed in a nuclear reactor?
By removing the fuel rods
By inserting the control rods
By cooling the reactor down
Apart from uranium, which other element is commonly used as fuel in fission reactors?
Plutonium
Mercury
Iron
Why is the reactor filled with graphite?
To speed up the neutrons
To slow down the neutrons
To stop the neutrons
What is nuclear fusion?
Where does fusion occur naturally?
In bombs
In stars
In power stations
Why does fusion only happen at very high temperatures?
Because it happens in stars
To overcome the repulsion of the positives
To increase the speed of the reaction
Where does the energy come from in fusion reactions?
Violent chemical reactions
Electrostatic potential energy
Some of the mass converts to energy