Molecular mass Molecular mass Relative molecular mass or molecular weight is the mass of a molecule. It is calculated as the sum of the relative atomic masses of each constituent element multiplied by the number of atoms of that element in the molecular formula. The molecular mass of small to medium size molecules, measured by mass spectrometry, determines stoichiometry. For large molecules such as proteins, methods based on viscosity and light-scattering can be used to determine molecular mass when crystallographic data are not available. Both atomic and molecular masses are usually obtained relative to the mass of the isotope C (carbon 12),
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