| Another thing, what makes an element synthetic? Not being able to find it at all in nature? Or just in tiny amounts? Because: Technetium, Promethium, Neptunium and Plutonium are found in traces amounts in nature. But so are Astatine, Francium, Radon and Polonium (Of which are much shorter lived and rarer than those four and not on your list.) Its very hard to define something like Plutonium as synthetic or very rare. |