Silver nitrate is a colorless crystalline solid. It dissolves in water. Most silver compounds do not dissolve in water. It can get dark if light shines on it. It is an oxidizing agent. Most of the times the silver ion is reduced, but sometimes the nitrate ion is reduced. It reacts with copper to make silver crystals and copper(II) nitrate. It turns into silver, nitrogen dioxide, and oxygen when it is heated. It is the least expensive silver compound. It reacts with bases to make dark brown silver(I) oxide.