# tritium

/ˈtɹɪtiəm/ (US) · /tɹˈaɪtiəm/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/tritium
Updated: 2026-10-15

## Definition

a rare form of hydrogen that gives off radiation. Scientists use it in nuclear research and in some signs that glow without electricity.

For teachers: a radioactive isotope of hydrogen with one proton and two neutrons, decaying by beta emission with a half-life of about 12.3 years. Occurs in trace amounts naturally and is produced artificially for fusion research, luminous devices and scientific tracers.

## Examples

- Tritium makes some emergency signs glow in the dark.
- The laboratory stores tritium in sealed steel containers to prevent leaks during fusion experiments.
- Because tritium decays relatively quickly, researchers must account for its declining concentration when calibrating long-term environmental tracers in ocean circulation models.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.