No. You start with copper, and when you are finished it is still copper, so there is no chemical change. It's a physical change. You changed the shape and moved some atoms around.
Yes it can; you simply have to reverse the reaction (upset Equilibrium); using whatever means you have available. All Chemical Reactions are reversible.
No. Burning of platinum wire is not a chemical change. It is a physical change. This is because no new substance is formed on burning of the platinum wire. It simply glows on being heated. Once...
Chemical Changes the release of gas greater changes of heat the generation of light a change of color the formation of a precipitate These are chemical changes because they change the substance's...