Aluminum oxide (Al2O3) is a compound made up of aluminum and oxygen atoms. Aluminum sulfate (Al2(SO4)3) is a salt made up of aluminum, sulfur, and oxygen atoms. Aluminum hydroxide (Al(OH)3) is a compound made up of aluminum, hydrogen, and oxygen atoms. Potassium aluminate (KAlO2) is a compound made up of potassium, aluminum, and oxygen atoms. These compounds are all related to aluminum and various other elements.