I am wondering what is number 1 copper and what is number 2 copper? What does it mean? What kind of copper is in a penny?
Copper is a transition metal, which means it can exist in two oxidation states. Copper 1 has a valence of 1 (meaning it has 1 electron in its outer shell) and Copper 2 has a valence of 2 (meaning it has 2 electrons in its outer shell.) The Copper in a penny is just copper. the valence doesn't come into play unless it is bonded with another element.
