Do different atomic numbers, #Z#, specify different elements? How are isotopes differentiated?
My word yes.....
We differentiate elements by their atomic number,
On the other hand, a given element may contain variable numbers of neutrons, which are massive nuclear particles of ZERO charge. Protons and neutrons, at nuclear ranges, engage in the strong nuclear force, which binds the nucleus together, and is demonstrably stronger than the electrostatic force.
A nucleus may contain VARIABLE numbers of neutrons, and this gives rise to the phenomenon of isotopes...
And isotopes are best illustrated by their occurrence in the simplest element, hydrogen. All hydrogen nuclei contain ONE nuclear proton, i.e.