| English | Nuclear fission |
|---|---|
| Bahasa Melayu | Pembelahan nukleus |
| 中文 | 核裂变 |
Definition
The splitting of a heavy nucleus into two lighter nuclei, releasing a large amount of energy.
In exam terms
Nuclear fission is the splitting of a heavy nucleus into two lighter nuclei, releasing a large amount of energy. It usually happens when a heavy nucleus such as ²³⁵U absorbs a slow neutron, becomes unstable and splits, also releasing two or three neutrons.
Energy is measured in joules (J). The energy comes from a small loss of mass, from E = mc².
A correct sentence: "The neutrons released in fission can trigger further fission, producing a chain reaction." This is the process used in nuclear power stations to generate electricity.
Do not confuse it with…
Do not confuse nuclear fission with nuclear fusion. Fission splits a heavy nucleus into lighter ones; fusion joins two light nuclei (such as hydrogen) into a heavier one, which is what powers the Sun.
Also distinguish fission from ordinary radioactive decay, where a nucleus only emits a small particle rather than splitting roughly in half.
In Paper 2 you may be asked to define nuclear fission, explain how a chain reaction occurs, or state the source of the released energy.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)