strontium 90

noun

, Chemistry.

1. a harmful radioactive isotope of strontium, produced in certain nuclear reactions and present in their fallout.

strontium 90

1. A radioactive isotope of strontium having a mass number of 90 and a half-life of 28 years. Strontium 90 is the most dangerous component of the fallout from nuclear explosions because it is easily absorbed by the body. It is also used in medicine to treat cancer.

Word History and Origins

Origin of strontium 90¹

First recorded in 1950–55

Example Sentences

It was established that strontium-90 and cesium-137, important in fallout on land, enter the marine cycles only in minute amounts.

From Project Gutenberg

Much attention has been devoted to strontium-90 and to its availability to man by deposit on plants and soils.

From Project Gutenberg

Experiments and fallout observations show that strontium-90 does not penetrate soils deeply.

From Project Gutenberg

If this is true, strontium-90 may be contained in the deep currents and eventually will be brought again to the surface.

From Project Gutenberg