Neutron-to-Proton Ratio
The ratio of neutrons to protons in a nucleus, the principal determinant of its stability and decay mode.
Formula / equation
N / Z
Unit
Dimensionless
In depth
A nucleus with too many neutrons converts one into a proton by beta-minus decay, while one with too few converts a proton into a neutron by positron emission or electron capture. Either route moves the nuclide towards the band of stability.
Examples in the real world
Carbon-14 with a ratio of 1.33 decays by beta emission to nitrogen-14, whose ratio is 1.00.