اذا لم تجد ما تبحث عنه يمكنك استخدام كلمات أكثر دقة.
الرَّقَم الذَّرِّي 53:- a nonmetallic element belonging to the halogens; used especially in medicine and photography and in dyes; occurs naturally only in combination in small quantities (as in sea water or rocks) (Arabic WordNet)