noun Uncommon

isotope

EYE-suh-tohp

Isotope (noun) means one of two or more versions of a chemical element that have the same number of protons but a different number of neutrons. Example: “Carbon-14 is a radioactive isotope used to date ancient bones.”

noun

One of two or more versions of a chemical element that have the same number of protons but a different number of neutrons.

"Carbon-14 is a radioactive isotope used to date ancient bones."

"Uranium has several isotopes, some far more unstable than others."

How to use isotope

Learner’s notes

In plain EnglishA variant of a chemical element that has extra or fewer neutrons in its atoms, but the same number of protons.

Common pairings

radioactive isotope stable isotope

Word forms

isotoped past tense, isotopes plural, isotopes singular

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Fill the gap

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Carbon-14 is a radioactive _____ used to date ancient bones.

Etymology

From Greek iso- ("same") plus -tope ("place"), because isotopes occupy the same position in the periodic table. Coined in 1913 by chemist Frederick Soddy, building on a suggestion by physician Margaret Todd in 1909.

Origin: Greek · First attested 1913

Class of 1913 isotope joined the language around 1913.

autistic crossword Pollyanna

See the full Class of 1913 →

Rhymes for isotope

ope pope mope rope dope hope lope nope cope trope slope grope

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Frequently asked questions

What does “isotope” mean?

The word “isotope” means one of two or more versions of a chemical element that have the same number of protons but a different number of neutrons. In plain terms, a variant of a chemical element that has extra or fewer neutrons in its atoms, but the same number of protons.

How do you pronounce “isotope”?

“Isotope” is pronounced EYE-suh-tohp (/ˈaɪ.sə.toʊp/ in IPA).

How do you use “isotope” in a sentence?

Here is “isotope” used in a sentence: “Carbon-14 is a radioactive isotope used to date ancient bones.”

What part of speech is “isotope”?

“Isotope” is a noun.

Where does the word “isotope” come from?

The word “isotope” dates back to around 1913 and comes from Greek. From Greek iso- ("same") plus -tope ("place"), because isotopes occupy the same position in the periodic table. Coined in 1913 by chemist Frederick Soddy, building on a suggestion by physician Margaret Todd in 1909.

Is “isotope” a common word?

“Isotope” is an uncommon word in modern English.