isotope

[ ahy-suh-tohp ]

/ ˈaɪ səˌtoʊp /

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noun Chemistry.

any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in the nucleus, or different atomic weights. There are 275 isotopes of the 81 stable elements, in addition to over 800 radioactive isotopes, and every element has known isotopic forms. Isotopes of a single element possess almost identical properties.

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Origin of isotope

1910–15; iso- + -tope<Greek tópos place

OTHER WORDS FROM isotope

i·so·top·ic

[ahy-suh-top-ik], /ˌaɪ səˈtɒp ɪk/, adjectivei·so·top·i·cal·ly, adverb

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use isotope in a sentence

So by seeing how much isotopes in the meteorite have changed, they can see how long it’s been careening through space.
Pristine 'fireball’ meteorite contains extraterrestrial organic compounds|Rachael Zisk|October 29, 2020|Popular-Science
Back in 1985, she co-authored a paper examining the isotopes of charred plant remains collected from the inside of pots.
Studying clay-pot residues could help scientists recreate ancient recipes|Jennifer Ouellette|September 29, 2020|Ars Technica
Then, the team established the link between this oxygen isotope record and sea ice extent.
Bering Sea winter ice shrank to its lowest level in 5,500 years in 2018|Carolyn Gramling|September 3, 2020|Science News
The relative values of those isotopes in the rainfall change depending on atmospheric conditions, and as plants take up that oxygen from the air, they record those changes.
Bering Sea winter ice shrank to its lowest level in 5,500 years in 2018|Carolyn Gramling|September 3, 2020|Science News

There, they chemically labeled larvae with a rare type, or isotope, of nitrogen.
When prey get scarce, these jellies become cannibals|Erin Garcia de Jesus|June 1, 2020|Science News For Students
Radiation dissipates over time with every isotopic half-life.
Radioactive Tuna Won’t Kill You—but Should We Be Concerned About Mercury?|Daniel Stone|May 30, 2012|DAILY BEAST
Isotopic sources produce neutrons as the result of a nuclear reaction.
The Atomic Fingerprint|Bernard Keisch

British Dictionary definitions for isotope

isotope

/ (ˈaɪsəˌtəʊp) /

noun

one of two or more atoms with the same atomic number that contain different numbers of neutrons

Derived forms of isotope

isotopic (ˌaɪsəˈtɒpɪk), adjectiveisotopically, adverbisotopy (aɪˈsɒtəpɪ), noun

Word Origin for isotope

C20: from iso- + Greek topos place

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for isotope

isotope

[ ī′sə-tōp′ ]

One of two or more atoms that have the same atomic number (the same number of protons) but a different number of neutrons. Carbon 12, the most common form of carbon, has six protons and six neutrons, whereas carbon 14 has six protons and eight neutrons. Isotopes of a given element typically behave alike chemically. With the exception of hydrogen, elements found on Earth generally have the same number of protons and neutrons; heavier and lighter isotopes (with more or fewer neutrons) are often unstable and undergo radioactive decay.

Cultural definitions for isotope

isotope

[ (eye-suh-tohp) ]

In physics, different forms of the same element, with nuclei that have the same number of protons but different numbers of neutrons. Isotopes are distinguished from each other by giving the combined number of protons and neutrons in the nucleus. For example, uranium 235 is the isotope of uranium that has 235 protons and neutrons in its nucleus rather than the more commonly occurring 238. All elements have isotopes.