Isotopes are defined within nuclear chemistry and physics as nuclides of a specific element that share identical atomic numbers (and thus proton counts) but possess distinct mass numbers due to varying neutron counts. This theoretical framework establishes that while isotores exhibit invariant chemical properties dictated by electron configuration determined by the number of protons, they display divergent nuclear stability and radiological behaviors governed strictly by their neutronic composition. The concept operates under the rule that elemental identity is solely a function of atomic number ($Z$), whereas mass variance reflects changes only in the nucleon count within the nucleus.
Isotopes are defined within nuclear chemistry and physics as nuclides of a specific element that share identical atomic numbers (and thus proton counts) but possess distinct mass numbers due to varyi…