isomer

i·so·mer  (s-mr)

n.

1. Chemistry 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.

2. Physics 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.

---

[Greek somers, having equal share : so-, iso- + meros, part, share; see (s)mer-² in Indo-European roots.]

---

iso·meric (-mrk) adj.

iso·meri·cal·ly adv.

---

isomer [ice-oh-mer]

Noun

Chem a substance whose molecules contain the same atoms as another but in a different arrangement

isomeric adj

---

isomer  (s-mr)

Any of two or more compounds, such as lactose and sucrose, composed of the same elements in the same proportions but differing in structure and other properties. There are two types of isomers, structural isomers and stereoisomers.

Thesaurus

Noun

1.

isomer - a compound that exists in forms having different arrangements of atoms but the same molecular weight chemical compound, compound - (chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight