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.
See also. 1  Isotopes (nuclides having the same number of protons) 2  Isotones (nuclides having the same number of neutrons) 3  Nuclear isomers (different excited states of the same nuclide) 4  Magic number (physics) 5  Electron capture.