the number two; 2

(bound form) sulfur; a nonmetallic chemical element with the symbol S

(bound form) a group of atoms that behave as a single unit in a chemical reaction; a radical

Chemical prefix denoting an organic group containing three carbon atoms, such as propyl or propane

(bound form) sulfur; commonly written as 硫黄 liú​huáng

acid, a chemical compound that releases hydrogen ions in water

sodium; natrium (chemical element Na)