Could a nuclear chemist convert a naturally occuring element into an unstable one?
It is not a matter of chemistry as much as a matter of irradiating the material with neutrons such that the nucleus of the material absorbs an extra neutron or two. Typically that would tend to make the element unstable. Each such absorption of an extra neutron creates a different isotope of that element, and each isotope can also be set to a different energy level, sometimes referred to different nuclides for that isotope or element. By the way, some naturally occurring elements are in themselves already unstable, which is one reason why we have to pay attention to radon buildup in our homes and generally have a lot of background radiation in general to contend with.
