Question

an isotope's proton count allows us to ____ the atom

Answer 1

Proton count = the identity of that element what that element is.

Neutrons can change and that's the definition of an isotope. Something that has different number of neutrons.

#of electrons can change too. That's what an ion is can be positive loss of an electron to give a positive charge or gaining an electron to have a negative charge an anion.