Isotopes of nihonium

Nihonium (₁₁₃Nh) is a synthetic element. Being synthetic, a standard atomic weight cannot be given and like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was ²⁸⁴Nh as a decay product of ²⁸⁸Mc in 2003. The first isotope to be directly synthesized was ²⁷⁸Nh in 2004. There are 6 known radioisotopes from ²⁷⁸Nh to ²⁸⁶Nh, along with the unconfirmed ²⁸⁷Nh and ²⁹⁰Nh. The longest-lived isotope is ²⁸⁶Nh with a half-life of 9.5 seconds.