Fission & Fusion Flashcards
(14 cards)
What is nuclear fission?
The splitting of a large atomic nucleus into two smaller nuclei, releasing energy
What element is commonly used as fuel in nuclear fission reactors?
Uranium-235 (or sometimes Plutonium-239).
What is a key product of nuclear fusion?
Helium and a large amount of energy.
What conditions are required for nuclear fusion?
Very high temperature and high pressure.
What starts a chain reaction in nuclear fission?
A neutron colliding with and splitting another nucleus.
Describe briefly what happens during uranium-235 fission.
The nucleus absorbs a neutron, splits into two smaller nuclei, and releases 2–3 neutrons and energy.
Give two differences between nuclear fission and fusion.
Fission splits atoms; fusion joins them.
Fission is used in reactors; fusion powers stars.
Why is fusion hard to achieve on Earth?
It requires extremely high temperatures and pressures to overcome the electrostatic repulsion between nuclei.
What is a chain reaction in nuclear fission?
A process where released neutrons from one fission event cause more nuclei to split, continuing the reaction.
One advantage of fusion over fission?
Produces less radioactive waste.
What are control rods used for in a nuclear reactor?
To absorb excess neutrons and control the rate of the fission chain reaction.
What is the function of the fuel rods in a nuclear reactor?
They contain fissile material (like uranium-235) where fission reactions occur, releasing energy.
What is the role of the moderator in a nuclear reactor?
It slows down fast neutrons so they are more likely to be absorbed by uranium nuclei to sustain the chain reaction.
What does the coolant do in a nuclear reactor?
It transfers heat away from the reactor core to the heat exchanger, where steam is produced to drive turbines.
