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

isotopic

ˌī-sə-ˈtä-pik  -ˈtō- 

adjective

isotopically

ˌī-sə-ˈtä-pi-k(ə-)lē  -ˈtō- 

adverb

Examples of isotope in a Sentence

Recent Examples on the Web

And that’s just the tip of the—isotope. — Jordan Blum, Fortune, 13 June 2026

This makes the ratio of these two isotopes in sediments a measure of the organic carbon weathering at the time. — Howard Lee, ArsTechnica, 26 June 2026

Hecla said his calculations show that a direct-cycle system would produce large quantities of radioactive isotopes of argon, krypton and carbon. — Geoff Brumfiel, NPR, 18 June 2026

The comet contains far more heavy hydrogen—in the form of an isotope called deuterium, which has one neutron and one proton—than any local space rock, a quality that tends to point to colder environs. — Joseph Howlett, Scientific American, 22 June 2026

Word History

Etymology

is- + Greek topos place

First Known Use

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