Meaning-based. The second half also names a property of the element. Refers to 轻 “light-weight”, the lightest element
History of the character
Every form found in the sources, from the first missionary chemistry books of the 1850s to the current
standards. Hover a dot for the source. Simplified 氢, traditional 氫.
1855水母氣shuǐmǔqì博物新編 Bówù Xīnbiān, Benjamin Hobson (合信)“water-mother gas”, a calque of hydro-gen
1855輕氣qīngqì博物新編 Bówù Xīnbiān, Benjamin Hobson (合信)“light gas”; the lightest element
1868淡氣格物入門 Géwù Rùmén, W. A. P. Martin (丁韙良), Tongwen College
1870輕氣化學初階 Huàxué Chūjiē, John G. Kerr (嘉約翰) & Hé Liǎorán (何瞭然)
1871輕氣金石識別 Jīnshí Shíbié, D. J. MacGowan (瑪高溫) & Huà Héngfāng (華蘅芳)
1871輕氣化學鑑原 Huàxué Jiànyuán, Xú Shòu (徐壽) & John Fryer (傅蘭雅), Jiangnan Arsenal
1933氫qīng化學命名原則 Principles of Chemical Nomenclature, Zhèng Zhènwén (鄭貞文), National Institute for Compilation and Translation气 + the phonetic 巠 taken from 輕. A form with the whole 輕 under 气 was used briefly.
Homophones
No other element shares this syllable.
Elsewhere
Japanese水素Korean수소Vietnamesehydro
Western name from Greek via Latin and French ὕδωρ (root: ὑδρ-) + γενής (hydor genes), “water + begetter”. Compare all