Mass number number of protons in a nucleus, and thus uniquely identifies an element. Hence, the difference between the mass number and the atomic number gives the number of neutrons ("N") in a given nucleus: . The mass number is written either after the element name or as a superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or , which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number ("Z") as a subscript to the left of the element symbol directly below the mass number:
Isotopes of tennessine Isotopes of tennessine Tennessine (Ts) is the most-recently synthesized synthetic element, and much of the data is hypothetical. As for any synthetic element, a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first (and so far only) isotopes to be synthesized were Ts and Ts in 2009. The longer-lived isotope is Ts with a half-life of 51 ms. The below table contains various combinations of targets and projectiles that could be used to form compound nuclei with atomic number 117. Between July 2009 and February 2010, the team at the JINR (Flerov