isotope

1 of 2

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

isotopic

ˌī-sə-ˈtä-pik  -ˈtō- 

adjective

isotopically

ˌī-sə-ˈtä-pi-k(ə-)lē  -ˈtō- 

adverb

isotopic

2 of 2

adjective

iso·​topic

-¦tōp-

: of, relating to, or having the relationship of an isotope

isotopically

-pə̇k(ə)lē 

adverb

Examples of isotope in a Sentence

Recent Examples on the Web

Noun

Yet, the oxygen isotopes in these primitive samples remained virtually untouched by parent-body alteration. — Mrigakshi Dixit, Interesting Engineering, 22 Sep. 2026

Carbon isotopes even showed the dietary signal expected from predators. — Jacek Krywko, ArsTechnica, 20 Sep. 2026

These medicines work by delivering radioactive isotopes directly to cancer cells. — Allison Deangelis, STAT, 20 Sep. 2026

The study looked at bonds between carbon and oxygen isotopes in the fossil. — Corinne Purtill follow, Los Angeles Times, 16 Sep. 2026

Word History

Etymology

Noun

is- + Greek topos place

Adjective

International Scientific Vocabulary isotope + -ic

First Known Use

Noun

1913, in the meaning defined at sense 1

Rhymes for isotope

• antelope
• bronchoscope
• cantaloupe
• cystoscope
• endoscope
• envelope
• epitope
• gyroscope
• horoscope
• microscope
• misanthrope
• pericope

Kids 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

isotopic

ˌī-sə-ˈtäp-ik 

-ˈtō-pik

adjective

isotopically

-ˈtäp-i-k(ə-)lē 

-ˈtō-pi-

adverb

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

isotopic

ˌī-sə-ˈtäp-ik  -ˈtō-pik 

adjective

isotopically

-ˈtäp-i-k(ə-)lē  -ˈtō-pi- 

adverb

isotopy

ˈī-sə-ˌtō-pē  ī-ˈsät-ə-pē 

noun

plural isotopies