Carbon-12 Carbon-12 Carbon-12 (C) is the more abundant of the two stable isotopes of carbon (Carbon-13 being the other), amounting to 98.93% of the element carbon; its abundance is due to the triple-alpha process by which it is created in stars. Carbon-12 is of particular importance in its use as the standard from which atomic masses of all nuclides are measured, thus, its atomic mass is exactly 12 daltons by definition. Its nucleus contains 6 protons and 6 neutrons. Before 1959 both the IUPAP and IUPAC used oxygen to define the mole; the chemists defining the mole as the number of
Isotopes of livermorium Isotopes of livermorium Livermorium (Lv) is an artificial element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was Lv in 2000. There are four known radioisotopes from Lv to Lv, as well as a few suggestive indications of a possible heavier isotope Lv. The longest-lived of the four well-characterised isotopes is Lv with a half-life of 53 ms. The below table contains various combinations of targets and projectiles which could be used to form compound nuclei with atomic number 116. In 1998, the team