isomerism

American  

[ahy-som-uh-riz-uhm] / aɪˈsɒm əˌrɪz əm /

noun

1. Chemistry. the relation of two or more compounds, radicals, or ions that are composed of the same kinds and numbers of atoms but differ from each other in structural arrangement structural isomerism, as CH 3 OCH 3 and CH 3 CH 2 OH, or in the arrangement of their atoms in space and therefore in one or more properties.

2. Also called nuclear isomerism.  Physics. the relation of two or more nuclides that have the same atomic number and mass number but different energy levels and half-lives.

3. Chemistry, Physics. the phenomenon characterized by such a relation.

4. the state or condition of being isomerous.

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isomerism British  

/ aɪˈsɒməˌrɪzəm /

noun

1. the existence of two or more compounds having the same molecular formula but a different arrangement of atoms within the molecule See also stereoisomerism optical isomerism

2. the existence of two or more nuclides having the same atomic numbers and mass numbers but different energy states

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Etymology

Origin of isomerism

First recorded in 1830–40; isomer(ic) + -ism

Example Sentences

Four carbon atoms in the chain of butene allows for the formation of isomers based on the position of the double bond, as well as a new form of isomerism.

From Textbooks • Feb. 14, 2019

Such as: the meaning of isomerism; what a categorical syllogism is; and who the Hanseatic League were.

From The Guardian • Apr. 6, 2010

What they discovered were new examples of nuclear isomerism, in which isotopes of identical mass numbers and changes show dramatically different radioactive characteristics.

From "Big Science" by Michael Hiltzik

One of these is structural isomerism, and the other is space- or stereo-isomerism.

From The Chemistry of Plant Life by Thatcher, Roscoe Wilfred

Further, the allotropic modifications of elements and the isomerism of compounds increased the difficulties.

From Scientific American Supplement, No. 643, April 28, 1888 by Various