sodium (n.)youdaoicibaDictYouDict[sodium 词源字典]
metallic alkaline element, 1807, coined by English chemist Humphry Davy from soda; so called because the element was isolated from caustic soda (sodium hydroxide). The chemical symbol Na is from natrium, alternative name for the element proposed by Berzelius from natron, a name of a type of soda.[sodium etymology, sodium origin, 英语词源]