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
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
Building a Treasure Map Helium-3 is an isotope of helium that possesses one fewer neutron than its run-of-the-mill counterpart, helium-4, which is the only other stable helium isotope.
—Robin George Andrews, Scientific American, 14 May 2026
To answer that, the researchers turned to stable isotope analysis, a method that traces the chemical signatures of food through an animal’s body.
—Melissa Cristina Márquez, Forbes.com, 6 May 2026
See All Example Sentences for isotope
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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
Building a Treasure Map Helium-3 is an isotope of helium that possesses one fewer neutron than its run-of-the-mill counterpart, helium-4, which is the only other stable helium isotope.
—Robin George Andrews, Scientific American, 14 May 2026
To answer that, the researchers turned to stable isotope analysis, a method that traces the chemical signatures of food through an animal’s body.
—Melissa Cristina Márquez, Forbes.com, 6 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 5 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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