halogen

Any of five related nonmetallic elements (fluorine, chlorine, bromine, iodine, or astatine) that are all monovalent and readily form negative ions.

• 🇨🇳卤素，指周期表中第17族（VIIA族）的五种非金属元素：氟、氯、溴、碘和砹，它们均为单价，易形成负离子。

1. Nonmetallic chemical element group B2 formal scientific

   One of five related nonmetallic elements (fluorine, chlorine, bromine, iodine, or astatine) that are all monovalent and readily form negative ions.

   • Fluorine is the most reactive of all halogens.
   • Chlorine, a halogen, is widely used in water treatment.
   • Iodine is an essential halogen for thyroid function.

   🇨🇳卤族元素

• halogens plural form
• halogens' possessive plural form
• halogen's possessive singular form