Isomer

Last revised by Calum Worsley ◉ on 11 Jan 2023

Citation, DOI, disclosures and article data

Citation:

Vajuhudeen Z, Worsley C, Chieng R, et al. Isomer. Reference article, Radiopaedia.org (Accessed on 05 Jun 2023) https://doi.org/10.53347/rID-79808

DOI:

https://doi.org/10.53347/rID-79808

Permalink:

https://radiopaedia.org/articles/79808

rID:

79808

Article created:

5 Jul 2020, Zemar Vajuhudeen

Disclosures:

At the time the article was created Zemar Vajuhudeen had no recorded disclosures.

View Zemar Vajuhudeen's current disclosures

Last revised:

11 Jan 2023, Calum Worsley ◉

Disclosures:

At the time the article was last revised Calum Worsley had no recorded disclosures.

View Calum Worsley's current disclosures

Revisions:

6 times, by 4 contributors - see full revision history and disclosures

Sections:

Imaging Technology

Synonyms:

Isomerism (physics)
Nuclear isomerism

In nuclear physics, isomers are atomic species that are identical in nuclear composition, sharing the same mass and atomic numbers, but differ in their relative energy states, and will therefore differ in their manner of radioactive decay.

Examples of isomers include:

metastable technetium-99, which decays into technetium-99 with a half-life of 6 hours by emission of gamma rays ^4,5
metastable krypton-81, which decays into krypton-81 with a half-life of 13 seconds also by releasing gamma rays ⁵

This term should not be confused with the similarly sounding isotope, isobar and isotone.

The term should also not be confused with isomerism in organic chemistry, which describes molecules with an identical chemical formula but differ from one another with respect to spatial configuration.