noun

fission

FIH-shuhn

noun

The splitting of an atomic nucleus into smaller pieces, releasing large amounts of energy.

"Nuclear power plants generate electricity through controlled fission."

"The bomb worked by triggering rapid nuclear fission."

The splitting of a single cell or item into two separate parts.

"The bacterium reproduces by fission, dividing into two identical cells."

How to Use Fission

Learner’s notes

In plain EnglishSplitting one thing into two, especially an atom's nucleus (releasing energy) or a cell (reproducing).

Common mistake

Don't confuse with fusion, which is the opposite process — combining nuclei rather than splitting them.

Easily confused with

fusion →

Common pairings

nuclear fission binary fission fission reactor

fissioned past tense, fissions plural, fissions singular

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Can you complete this real example?

Nuclear power plants generate electricity through controlled _____.

From Latin fissio, "the act of splitting," from findere, "to split" — the same root behind "fissure."

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