Isotone


Two nuclides are said to be isotones if they have the same neutron number NN but different proton numbers ZZ (equivalently, different atomic mass number AA). For example, the stable isotones with N=1N=1 are deuterium \ce12H1\ce{^{2}_{1}H_{1}} and helium-3 \ce23He1\ce{^{3}_{2}He}_{1}.