isomerism

[ ahy-som-uh-riz-uhm ]

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. Compare optical isomerism, stereoisomerism.
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.

isomerism

/ aɪˈsɒməˌrɪzəm /

noun

1. See optical isomerism, stereoisomerism
   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

Word History and Origins

Origin of isomerism¹

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

Example Sentences

A further distinction is necessary to a survey of the subdivisions of isomerism regarded in its widest sense.

From Project Gutenberg

There are subtle and more subtle differences causing isomerism.

From Project Gutenberg

Before entering into detail it may be useful to consider the nature of isomerism from a general standpoint.

From Project Gutenberg

A general philosophical interest is attached to the phenomena of isomerism.

From Project Gutenberg

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

From Project Gutenberg