isotope
noun
iso·tope
ˈī-sə-ˌtōp 
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
: nuclide
Examples of isotope in a Sentence
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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
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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
Cite this Entry
“Isotope.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/isotope. Accessed 12 Mar. 2025.
Copy CitationKids Definition
isotope
noun
iso·tope
ˈī-sə-ˌtōp
: any of the forms of an element that differ in the number of neutrons in an atom
Medical Definition
isotope
noun
iso·tope
ˈī-sə-ˌtōp
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
: nuclide
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