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
Alongside neutrinos, radioactive decay produces isotopes that could enhance cancer diagnostics and imaging techniques.
—
Neetika Walter, Interesting Engineering, 9 Sep. 2025
Core samples and isotope-dating of the metal-rich carbonatites recently discovered in Australia’s Northern Territory indicate that the rocks traveled near the Earth’s surface between 830 and 820 million years ago.
—Laura Baisas, Popular Science, 3 Sep. 2025
Val Finlayson is an assistant research scientist in high-temperature isotope geochemistry, marine geology and tectonics with the Department of Geology at the University of Maryland.
—Mark Price, Miami Herald, 2 Sep. 2025
One of the problems with nuclear fusion is getting the reaction started, which requires a heavy concentration of the hydrogen isotope deuterium.
—New Atlas, 29 Aug. 2025
See All Example Sentences for isotope
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Neetika Walter, Interesting Engineering, 9 Sep. 2025
Core samples and isotope-dating of the metal-rich carbonatites recently discovered in Australia’s Northern Territory indicate that the rocks traveled near the Earth’s surface between 830 and 820 million years ago.
—Laura Baisas, Popular Science, 3 Sep. 2025
Val Finlayson is an assistant research scientist in high-temperature isotope geochemistry, marine geology and tectonics with the Department of Geology at the University of Maryland.
—Mark Price, Miami Herald, 2 Sep. 2025
One of the problems with nuclear fusion is getting the reaction started, which requires a heavy concentration of the hydrogen isotope deuterium.
—New Atlas, 29 Aug. 2025
See All Example Sentences for isotope
Cite this Entry
“Isotope.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/isotope. Accessed 10 Sep. 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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