Isodiapher

Nuclear physics
Nucleus · Nucleons (p, n) · Nuclear force · Nuclear reaction
Nuclear models and stability Liquid drop · Nuclear shell · Nuclear structure Binding energy · p–n ratio · Drip line · Stability Isl.
Nuclides' classification Isotopes – equal Z Isobars – equal A Isotones – equal N Isodiaphers – equal N − Z      Isomers – equal all the above Mirror nuclei – Z ↔ N Stable · Magic · Even/odd · Halo
Radioactive decay Alpha α · Beta β (2β, β+) · K/L capture · Isomeric (Gamma γ · Internal conversion) · Spontaneous fission · Cluster decay · Neutron emission · Proton emission Decay energy · Decay chain · Decay product · Radiogenic nuclide
Nuclear fission Spontaneous · Products (pair breaking) · Photofission
Capturing processes electron · neutron (s · r) · proton (p · rp)
High energy processes Spallation (by cosmic ray) · Photodisintegration
Nucleosynthesis topics Nuclear fusion Processes: Stellar · Big Bang · Supernova Nuclides: Primordial · Cosmogenic · Artificial
Scientists Becquerel · Davisson · Bethe · Skłodowska-Curie · Pi.Curie · Fr.Curie · Ir.Curie · Fermi · Oppenheimer · Rutherford · Thomson  · Chadwick · Oliphant · Szilárd  · Teller · Lawrence · Proca · Mayer · Jensen · Alvarez · Soddy · Rabi · Meitner · Strassmann · Hahn · Purcell · Walton · Cockcroft ·
v t e

In nuclear physics, isodiaphers refers to nuclides which have different atomic numbers and mass numbers but the same neutron excess, which is the difference between numbers of neutrons and protons in the nucleus. For example, for both 234
90Th and 238
92U the difference between the neutron number (N) and proton number (Z) is N − Z = 54.

One large family of isodiaphers has zero neutron excess, N = Z. It contains many primordial isotopes of elements up to calcium. It includes ubiquitous 12
6C, 16
8O, and 14
7N.

The daughter nuclide of an alpha decay is an isodiapher of the original nucleus. Similarly, beta decays (and other weak-force-involving decays) produce isobars.

The difference between number of neutrons and protons is called isotopic number.^{[citation needed]}