uranium 235

noun

: a light isotope of uranium of mass number 235 that constitutes less than one percent of natural uranium, that when bombarded with slow neutrons undergoes rapid fission into smaller atoms with the release of neutrons and energy, and that is used in nuclear reactors and atomic bombs

Examples of uranium 235 in a Sentence

Recent Examples on the Web

Enrichment involves concentrating the uranium 235. — Stephanie Pappas, Scientific American, 23 Apr. 2026

Space reactor challenge Fuel rods made with uranium 235 oxide distributed in a metal or ceramic matrix comprise the core of a standard fission reactor. — Jacek Krywko, Ars Technica, 22 July 2024

Perhaps the most audacious study of cosmic rays was carried out in 1931, by Auguste Piccard, Bertrand’s grandfather, an eccentric, bespectacled physicist who wrote several groundbreaking scientific papers and predicted the existence of uranium 235. — Ben Taub, The New Yorker, 3 Oct. 2022

Increasing the proportion of uranium 235 is known as enrichment. — BostonGlobe.com, 5 Nov. 2019

Word History

First Known Use

1940, in the meaning defined above

Kids Definition

uranium 235

noun

: a light form of uranium of mass number 235 that when bombarded with neutrons splits rapidly into smaller atoms with the release of neutrons and atomic energy

Medical Definition

uranium 235

noun

: a light isotope of uranium of mass number 235 that when bombarded with slow neutrons undergoes rapid fission into smaller atoms with the release of neutrons and energy