Open AccessHo Ho Ho! When Water Was Diatomic
Author(s) -
Edwin C. Constable
Publication year - 2021
Publication title -
chimia
Language(s) - English
Resource type - Journals
eISSN - 2673-2424
pISSN - 0009-4293
DOI - 10.2533/chimia.2021.1052
Subject(s) - diatomic molecule , confusion , atomic units , valency , hydrogen , oxygen , atomic oxygen , atomic physics , chemistry , physics , quantum mechanics , philosophy , molecule , psychology , linguistics , psychoanalysis
When he introduced the concept of atomic weights at the beginning of the 19th Century CE, John Dalton assumed that water had the formula HO. This assumption resulted in a half century of confusion – partly because on a scale of H = 1, he defined the atomic weights O = 8 and C = 6, and partly because elements that could exhibit variable valency appeared to possess different atomic (or rather equivalent) weights. The correction of the formula of water, together with the recognition of the diatomic nature of the gases hydrogen and oxygen, were formalized following the Karlsruhe congress of 1861 and allowed the establishment of the "modern" and consistent atomic weights.