Two opposite tricks unlock the energy of the nucleus. Break a heavy nucleus apart and energy pours out, the engine of a reactor. Force light nuclei together and even more is released, the fire that lights the Sun.
Nuclear fission splits a large nucleus into smaller ones, releasing energy and neutrons that can trigger a chain reaction, the process in nuclear reactors. Nuclear fusion joins light nuclei into a heavier one, releasing energy, the process that powers the Sun and stars.
Nuclear fission is the splitting of a large nucleus into smaller nuclei, releasing energy and neutrons. Nuclear fusion is the joining of light nuclei into a heavier one, releasing energy.
The released neutrons from fission can cause further fission, a chain reaction. Fusion powers the Sun.
Trigger a fission split and a fusion join, and watch the energy released by each.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
Nuclear fission is the...
Nuclear fusion is the...
The process that releases the energy of the Sun is...
In fission, the neutrons released can go on to cause...
One breaks heavy nuclei apart, the other forces light nuclei together, and both give out energy.
| Fission | Fusion |
|---|---|
| Splits a large (heavy) nucleus | Joins light nuclei together |
| Releases energy and neutrons | Releases energy |
| Neutrons can cause a chain reaction | Needs very high temperature and pressure |
| Used in nuclear reactors | Powers the Sun and stars |
Fission splits a heavy nucleus while fusion joins light nuclei, the opposite processes, yet both release energy. Fusion needs extreme temperatures and pressures, which is why it happens in stars but is hard to achieve on Earth.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Which process joins light nuclei and releases energy?
A large uranium nucleus splits into two smaller nuclei and releases neutrons. This is...
Why is nuclear fusion difficult to achieve on Earth?
Fission and fusion complete the atom strand. Keep the chain going.