14Cn

14Cn is not a recognized isotope or chemical species. In standard nuclear notation, isotopes are written as X-A, where X is the element symbol and A is the mass number. For the superheavy element Copernicium (symbol Cn, atomic number 112), any legitimate isotope must have a mass number A that satisfies A = Z + N, with Z = 112. A designation like 14Cn would imply a mass number of 14, which would require a negative number of neutrons and is hence physically impossible. Consequently, 14Cn has no meaning in credible scientific literature.

Copernicium (Cn) is a synthetic, highly radioactive element. It was first produced in 1996 by researchers at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt and at JINR in Dubna, by bombarding heavy actinide targets with a calcium-48 beam. All observed isotopes of Copernicium are extremely unstable, with half-lives typically lasting milliseconds to seconds, and no stable isotope exists. Because of this instability, detailed chemical studies are challenging, and much of the understanding of Copernicium remains predictive.

Isotopes of Copernicium are designated using the form Cn-A, where A is the mass number (for example, Cn-281, Cn-282, etc.). The experimentally observed mass numbers for Copernicium lie in the low to mid 280s, well above 14. In summary, 14Cn is not a valid or observed designation within current science.