اذا لم تجد ما تبحث عنه يمكنك استخدام كلمات أكثر دقة.
العنصر السابع عشر:- a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water) (Arabic WordNet)