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
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
Space probes have long relied on radioactive isotopes to generate power where solar energy is unavailable.
—Aamir Khollam, Interesting Engineering, 1 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
The presence of these isotopes could help explain why certain unusual isotopes are left in fragments of the early solar system in the formation of meteorites and comets.
—Robert Lea, Space.com, 29 Aug. 2025
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.
Mark Price, Miami Herald, 2 Sep. 2025
Space probes have long relied on radioactive isotopes to generate power where solar energy is unavailable.
—Aamir Khollam, Interesting Engineering, 1 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
The presence of these isotopes could help explain why certain unusual isotopes are left in fragments of the early solar system in the formation of meteorites and comets.
—Robert Lea, Space.com, 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 9 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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share