Which of the properties of isotopes of an element is different?

Isotopes have the same number of protons but different numbers of neutrons, so their electronic configurations are identical. First ionisation enthalpy (A), effective nuclear charge (B), and electron affinity (C) depend primarily on the nuclear charge and electron configuration, which are the same for isotopes. However, melting and boiling points (D) depend on interatomic or intermolecular forces, which can vary due to mass differences (isotope effect). Heavier isotopes often have slightly higher melting and boiling points because of lower zero-point energy and stronger bonds. Therefore, melting point and boiling point differ among isotopes.