Neutron emission in the context of "Isotopes of oxygen"

There are three known stable isotopes of oxygen (₈O):
O,
O, and
O. Radioisotopes are known from O to O (particle-bound from mass number 13 to 24), and the most stable are
O with half-life 122.27 seconds and
O with half-life 70.62 seconds. All remaining radioisotopes are even shorter in lifetime. The four heaviest known isotopes (up to
O) decay by neutron emission to
O, whose half-life is 77 milliseconds; O, along with Ne, have been used in the model of reactions in the crust of neutron stars. The most common decay mode for isotopes lighter than the stable isotopes is β decay to nitrogen, and the most common mode after is β decay to fluorine.

In nuclear physics, the valley of stability (also called the belt of stability, nuclear valley, energy valley, or beta stability valley) is a characterization of the stability of nuclides to radioactivity based on their binding energy. Nuclides are composed of protons and neutrons. The shape of the valley refers to the profile of binding energy as a function of the numbers of neutrons and protons, with the lowest part of the valley corresponding to the region of most stable nuclei. The line of stable nuclides down the center of the valley of stability is known as the line of beta stability. The sides of the valley correspond to increasing instability to beta decay (β or β). The decay of a nuclide becomes more energetically favorable the further it is from the line of beta stability. The boundaries of the valley correspond to the nuclear drip lines, where nuclides become so unstable they emit single protons or single neutrons. Regions of instability within the valley at high atomic number also include radioactive decay by alpha radiation or spontaneous fission. The shape of the valley is roughly an elongated paraboloid corresponding to the nuclide binding energies as a function of neutron and atomic numbers.

The nuclides within the valley of stability encompass the entire table of nuclides. The chart of those nuclides is also known as a Segrè chart, after the physicist Emilio Segrè. The Segrè chart may be considered a map of the nuclear valley. The region of proton and neutron combinations outside of the valley of stability is referred to as the sea of instability.