halogen

Từ điển Oxford Learners Wordfinder Dictionary

noun

any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions (Freq. 2)
• Hypernyms:
group, grouping
• Hyponyms:
astatine, At, atomic number 85, bromine, Br,
atomic number 35, chlorine, Cl, atomic number 17, fluorine, F,
atomic number 9, iodine, iodin, I, atomic number 53