isomers: that series of Coleoptera in which the tarsi have an equal number of joints on all feet.
In the case of tetra-substituted compounds, thirty isomers are possible when all the groups are different.
One class of isomers was unexplained, and an explanation was demanded.
A factor of considerable importance in determining boiling-points of isomers is the symmetry of the molecule.
Here we have assumed the substituent groups to be alike; when they are unlike, a greater number of isomers is possible.
The oils drained from the crude naphthalene are re-distilled and worked for carbolic acid and its isomers.
The next members are the isomers anthracene and phenanthrene, C14H10, formed from three benzene nuclei.
The two pigments are, of course, isomers; but the difference in their structural arrangement is not known.
isomer i·so·mer (ī'sə-mər)
Any of two or more substances that are composed of the same elements in the same proportions but differ in properties because of differences in the arrangement of atoms.
Any of two or more nuclei with the same mass number and atomic number that have different radioactive properties and can exist in any of several energy states for a measurable period of time.