14Ne

14Ne is the not yet observed isotope of neon with mass number 14, an atom with Z = 10 protons and N = 4 neutrons. This combination places it far on the proton-rich side of the nuclear chart, where nuclei are typically highly unstable. In contemporary nuclear models, 14Ne is predicted to lie beyond the proton drip line for neon, meaning it would not be bound with respect to proton emission and could exist only as a very short-lived resonance if at all.

No bound state of 14Ne has been observed in experiments. Theoretical estimates indicate negative proton separation energies for configurations corresponding to 14Ne, implying rapid decay by emission of one or more protons. Consequently, any state of 14Ne would have an extremely brief lifetime, effectively rendering it unobservable as a stable or long-lived nucleus under normal conditions.

Experimental searches for very proton-rich neon isotopes have targeted isotopes near A = 14–16 through reactions such as projectile fragmentation and nucleon knockout. To date, these efforts have not produced a bound 14Ne, and its existence remains hypothetical. Studying such isotopes helps test and constrain models of the proton drip line and the structure of light nuclei at extreme proton-to-neutron ratios.

In summary, 14Ne is considered unbound and is not known to exist as a stable or long-lived nucleus; it serves as a theoretical marker for the boundaries of nuclear binding in the neon isotopic chain.