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.
The number of nucleons (both protons and neutrons) in the nucleus is the atom's mass number, and each isotope of a given element has a different mass number. For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively.or example, 14C is a radioactive form of carbon while 12C and 13C are stable isotopes. There are about 339 naturally occurring nuclides on Earth, of which 288 are primordial nuclides, meaning that they have existed since the solar system's formation.