What is the meaning of(II)in copper (II)Oxide?

The “I” and “II” in copper oxide represents the number of electrons that the metal has provided when copper oxide is brought into contact with metal. Some uses for copper oxide are: Building copper-based structures. These structures gradually change color due to oxidation.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

answer; talc and gypsum;