isotope

noun

iso·​tope ˈī-sə-ˌtōp How to pronounce isotope (audio)
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
isotopic adjective

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.
The smoking gun is an isotope of iron called iron-60, which has been found in large amounts on the seafloor. Michael Irving, New Atlas, 2 Mar. 2025 Radiation Surge The new paper, published in Astrophysical Journal Letters, examined iron isotopes (iron-60) to identify a 2.5 million-year-old supernova and connected it to a radiation surge that affected Earth around the same time. Jamie Carter, Forbes, 27 Feb. 2025 The rare radioactive isotope produced by cosmic rays in the atmosphere, is used to date objects millions of years old, because its half-life is 1.4 million years. Paul Smaglik, Discover Magazine, 10 Feb. 2025 Stable isotope evidence for pre-colonial maize agriculture and animal management in the Bolivian Amazon. Josh Hammer, Newsweek, 23 Dec. 2024 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 9 Mar. 2025.

Kids Definition

isotope

noun
iso·​tope ˈī-sə-ˌtōp How to pronounce isotope (audio)
: any of the forms of an element that differ in the number of neutrons in an atom
isotopic adjective
isotopically adverb

Medical Definition

isotope

noun
iso·​tope ˈī-sə-ˌtōp How to pronounce isotope (audio)
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
isotopic adjective
isotopically adverb
isotopy noun
plural isotopies

More from Merriam-Webster on isotope

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