A metal gives two chlorides A and B. A give black ppt. with NH3 and B gives white. With KI, B gives a yellow ppt, which is soluble in excess of KI. A and B are respectively

Most metals do not occur in their natural state. They are often found as compounds such as metal oxides, sulfides and halides.

Aluminium oxide is the main metal compound present in the ore known as bauxite. Iron pyrites or 'fool's gold' is mainly iron sulfide.