1
: any of two or more species of atoms of a chemical element with the same atomic number and nearly identical chemical behavior but with differing atomic mass or mass number and different physical properties
2

Examples of isotope in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Instead of using heavy elements like uranium, BOHR runs on the natural beta decay of tritium, a radioactive isotope of hydrogen. David Szondy july 07, New Atlas, 8 July 2026 Researchers at the Northwest Normal University, along with those at the Gansu Zhulong Technology in China, have built a new-generation nuclear battery using carbon-14 isotope and a silicon carbide (SiC) transducer. Ameya Paleja, Interesting Engineering, 8 July 2026 These isotopes can form through subtly different processes, at different times and in different locations in the galaxy. Keith Cooper, Space.com, 6 July 2026 Naturally occurring uranium is a mixture of multiple forms, or isotopes. Idaho Statesman, 29 June 2026 See All Example Sentences for isotope

Word History

Etymology

is- + Greek topos place

First Known Use

1913, in the meaning defined at sense 1

Time Traveler
The first known use of isotope was in 1913

Browse Nearby Words

Cite this Entry

“Isotope.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/isotope. Accessed 10 Jul. 2026.

Kids Definition

: any of the forms of an element that differ in the number of neutrons in an atom

Medical Definition

1
: any of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behavior but with differing atomic mass or mass number and different physical properties
2

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