uranium 238

American  

noun

Chemistry.

1. the radioactive uranium isotope having a mass number 238, comprising 99.28 percent of natural uranium: used chiefly in nuclear reactors as a source of the fissionable isotope plutonium 239.

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Etymology

Origin of uranium 238

First recorded in 1940–45

Example Sentences

See Examples For:

uranium 238

"The ratio of isotopes of uranium 238 to 225 on our planet is different than anywhere else in the universe because the two isotopes decay at different timescales," Brownless said.

From Salon ● Sep. 1, 2023

These neutrons have to penetrate an outer shield of uranium 238, which reduces their velocity, increases the bomb's explosive punch and releases harmful radioactivity.

From Time Magazine Archive

But plutonium, a man-made element created by bombarding uranium 238 with neutrons, has awesome properties.

From Time Magazine Archive

The elements were formed when neutrons from the explosion hit atoms of uranium 238 and were captured by its nucleus.

From Time Magazine Archive

Some of the uranium 238 atoms will absorb a stray neutron and undergo a series of transformations to become plutonium 239.

From "Meltdown" by Deirdre Langeland