Brainlag PlusHow a large nucleus splits, how a chain reaction is controlled in a reactor and runs away in a bomb, and how light nuclei join in the stars.
Fission
In fission a large, unstable nucleus such as uranium-235 or plutonium-239 splits into two smaller nuclei.
It is rare for this to happen by itself (spontaneous fission); usually the nucleus first absorbs a neutron.
The split gives two smaller nuclei, two or three neutrons, gamma rays and a lot of energy. The fission products all move off fast: the energy starts as kinetic energy.
23592U + 10n → 14156Ba + 9236Kr + 3 10n
- top: 235 + 1 = 236 and 141 + 92 + 3 = 236
- bottom: 92 + 0 = 92 and 56 + 36 + 0 = 92
The rest of this lesson and its 8 practice questions are in Plus.
Screen 1 of 4, free to read.
- 8 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards