Answer:
copper (I) oxide
Step-by-step explanation:
Copper (I) oxide or cuprous oxide (Cu2O) is a red or yellow chemical compound depending on the size of its particles. It is insoluble in water and organic solvents
It is found as the mineral cuprite in some red rocks. When exposed to oxygen, copper oxidizes naturally to copper (I) oxide, although very slowly. In the laboratory, the process can be accomplished in a much shorter time using high temperature or high oxygen pressure. With heating, it will form copper (II) oxide.
The formation of copper oxide (I) is the basis of the Fehling test and the Benedict reaction for the reduction of sugars that reduce a copper (II) salt in alkaline solution, giving a precipitate of Cu2O.