这个词是什么意思？
A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.
中文名称索引；定义为 MeSH 英文原文，尚未逐条译审。MESH:D006219 · MeSH 2026。
Courtesy of the U.S. National Library of Medicine. Annual snapshot; later updates may not be reflected. NLM does not endorse this service.