Standard atomic weight precise value is acceptable, CIAAW has published a single-number conventional atomic weight that can be used for example in trade. For hydrogen, . The twelve elements are: hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine and thallium. By using the abridged value, and the conventional value for the twelve interval values, a short IUPAC-defined value (5 digits plus uncertainty) can be given for all stable elements. In many situations, and in periodic tables, this may be sufficiently detailed. Standard atomic weight The standard atomic weight ("A", a relative atomic mass) is the atomic weight ("A") of a
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