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
Recent Examples on the Web
From studies with the James Webb Space Telescope's Near-Infrared Spectrometer (NIRSpec), Cordiner and his team measured both the ratio of carbon-12 to carbon-13 in 3I/ATLAS and also how enriched 3I/ATLAS's water is with the molecule deuterium, which is one of two stable isotopes of hydrogen.
—
Keith Cooper, Space.com, 30 Mar. 2026
The facility was then reclassified for medical isotope production.
—Sujita Sinha, Interesting Engineering, 30 Mar. 2026
Scientists hope to one day use these isotopes to generate an abundance of clean energy using advanced reactors.
—Victor Tangermann, Futurism, 25 Mar. 2026
The moon station will require radioactive isotope power sources, and eventually a nuclear reactor, to survive long periods of shadow on the lunar south pole.
—Dan Vergano, Scientific American, 24 Mar. 2026
See All Example Sentences for isotope
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.
Keith Cooper, Space.com, 30 Mar. 2026
The facility was then reclassified for medical isotope production.
—Sujita Sinha, Interesting Engineering, 30 Mar. 2026
Scientists hope to one day use these isotopes to generate an abundance of clean energy using advanced reactors.
—Victor Tangermann, Futurism, 25 Mar. 2026
The moon station will require radioactive isotope power sources, and eventually a nuclear reactor, to survive long periods of shadow on the lunar south pole.
—Dan Vergano, Scientific American, 24 Mar. 2026
See All Example Sentences for isotope
Cite this Entry
“Isotope.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/isotope. Accessed 5 Apr. 2026.
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
Love words? Need even more definitions?
Merriam-Webster unabridged
