10 Things You Didnât Know About Chronic Fatigue Syndrome. Chronic Fatigue Syndrome (CFS) is undeniably complicated in every conceivable way. The disorder has been around for decades, but the medical community has yet to assemble a clear picture of it. The condition is characterized by extreme fatigue that canât be explained by any underlying medical condition.
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable.
radioisotope. a radioactive form of an element, consisting of atoms with unstable nuclei, which undergo radioactive decay to stable forms, emitting characteristic alpha, beta, or gamma radiation.These may occur naturally, as in the cases of radium and uranium, or may be created artificially. radioactive form of an element, consisting of atoms with unstable nuclei, which undergo radioactive decay to stable forms, emitting characteristic alpha, beta, or gamma radiation.