What do two different neutral isotopes of the same element have in common?

nuclear mass

nuclear number

atomic number

atomic mass

The atom of each element is made up of electrons, protons and neutrons. All atoms of the same neutral element have the same number of protons and electrons but the number of neutrons can differ. Atoms of the same element but different neutrons are called isotopes. Because of these isotopes it becomes necessary to develop a notation to distinguish one isotope from another - the atomic symbol.

Isotopes are atoms of the same element that have the same number of nucleic protons, but different numbers of nucleic neutrons. This has the effect that they have a different mass number. However they have the same atomic number because that is a measure of how many protons are in the nucleus