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
Meghan Bartels, Scientific American, 9 June 2026
There are isotopes present that will also release additional neutrons, allowing this process to generate sufficient fuel.
—ArsTechnica, 9 June 2026
According to the team, each isotope produces a distinct resonance pattern when exposed to neutron beams across different energy levels.
—Georgina Jedikovska, Interesting Engineering, 28 May 2026
In a new study of some of this matter, researchers have found a byproduct of ancient supernovas, a radioactive iron isotope known as iron-60 (60Fe), that got stuck in the cloud and ended up embedded in Antarctic ice.
—Chelsea Gohd, Space.com, 18 May 2026
See All Example Sentences for isotope
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Noun
Then the researchers compared the ratios of two different isotopes of argon—which provides a chemical fingerprint that scientists can use to estimate the age of minerals in the rocks and thus of the hydrothermal system.
—Meghan Bartels, Scientific American, 9 June 2026
There are isotopes present that will also release additional neutrons, allowing this process to generate sufficient fuel.
—ArsTechnica, 9 June 2026
According to the team, each isotope produces a distinct resonance pattern when exposed to neutron beams across different energy levels.
—Georgina Jedikovska, Interesting Engineering, 28 May 2026
In a new study of some of this matter, researchers have found a byproduct of ancient supernovas, a radioactive iron isotope known as iron-60 (60Fe), that got stuck in the cloud and ended up embedded in Antarctic ice.
—Chelsea Gohd, Space.com, 18 May 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 14 Jun. 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
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