barium 140

American  

noun

Chemistry.

1. the radioactive isotope of barium having a mass number of 140 and a half-life of 12.8 days, used chiefly as a tracer.

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Example Sentences

The identification of the four isotopes by the Russian meteorological agency came 18 days after the explosion, and noted that samples taken in the city of Severodvinsk in the 15 days after the explosion contained strontium 91, barium 139, barium 140 and lanthanum 140.

From New York Times