This element's amphoteric trioxide is found in valentinite and senarmontite.
Pentostam, Repodral, and other drugs containing this compound preceded modern treatments like Praziquantel in the treatment of helminth infections. The trivalent chloride of this element can catalyze the reaction of aromatic amines with meso epoxides to yield beta-amino alcohols.  This element's amphoteric trioxide is found in valentinite and senarmontite. This element produces a false positive result in the Marsh assays since, like arsenic, it reacts with zinc and acid to produce a black precipitate. George Olah pioneered the combination of this element's pentafluoride with hydrogen fluoride to yield the strongest known superacid. It is commonly used to enhance the hardness of lead, and this Group Five element's sulfide is the ore stibnite. For ten points, name this metalloid, atomic number 51, with symbol Sb.
Pentostam, Repodral, and other drugs containing this compound preceded modern treatments like Praziquantel in the treatment of helminth infections.
antimony