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

These systems convert heat from the natural radioactive decay of isotopes into electricity. — Selam Gebrekidan, New York Times, 4 Oct. 2026

Drug developers also use accelerators to produce radiopharmaceuticals, which are drugs that contain a radioactive isotope. — Andrea Richard, The Conversation, 2 Oct. 2026

The supply of suitable isotopes, however, remains a major challenge for future spacecraft. — Aamir Khollam, Interesting Engineering, 2 Oct. 2026

These results matched the rock age found by isotope analysis. — Elizabeth Rayne, ArsTechnica, 30 Sep. 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