# uranium-235

> English word · Noun

## Definitions
1. A fissile isotope of uranium, used for energy generation and in atomic weapons, containing 143 neutrons. It has a half-life of 7.038×10⁸ years; it decays into thorium-231 and ultimately lead.

## Etymology
From uranium + 235 (the atomic mass of the isotope).

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/uranium-235