Magnesia, for example - or chemical a soldier may use on you (7) ANTACID. Problem about copper - short, fat and beefy (8) MUSCULAR. Only think I can see is CU for copper.
Sort of environmental activity that makes Ray racy! (6,7) CARBON CAPTURE. Shape of projectiong piece different on the outside (7) ELLIPSE. I know the def. is shape and ELL is a projecting piece. Don't...