triatomic, a. Chem.
(traɪəˈtɒmɪk)
[f. tri- + atom n. + -ic.]
a. Having three atoms in the molecule. † b. = trivalent. Obs. c. Containing three hydroxyl groups (OH); = trihydric a.1
| 1862 Miller Elem. Chem. (ed. 2) III. 53 To the triatomic group [of elements] belong nitrogen, phosphorus, arsenic, antimony, bismuth, and gold. 1863–72 Watts Dict. Chem. I. 464 To classify them [primary hydrides and chlorides] in four principal groups, thus: Monatomic, Diatomic, Triatomic, Tetratomic. 1872 Ibid. VI. 237 Nitrogen, which combines with 3 atoms of hydrogen, is triatomic, triadic, or trivalent. 1882 Roscoe Elem. Chem. xxxv. 320 The possible number of derivatives of the triatomic alcohols is much larger than that of either of the preceding classes. 1894 Times 18 Aug. 10/3 No doubt the passage of..the diatomic form of the substance to the triatomic form..takes place with evolution of heat. 1903 Edin. Rev. Oct. 393 It [radium] can ozonise oxygen—that is, condense it by rendering its molecules tri-atomic. |