Multiple choice atoms of isotopes can be distinguished from atoms of different elements because isotopes always have the same number of: protons as all other atoms of that same elementneutrons as all the other atoms of that same elementprotons and neutrons as all other atoms of that same elementprotons, neutrons and electrons as all other atoms of that same element

The correct answer is option A.

Atoms of isotopes can be distinguished from atoms of different  elements because isotopes always have the same number of protons as all other atoms of that same element.

Isotopes of different atoms of the same element have the same number of protons and electrons, but different numbers of neutrons.

Different isotopes of the same element have the same atomic number (as the number of protons are same) but different atomic masses (as the number of  neutrons are different and atomic mass is the summation of the number of protons and the number of neutrons).

just did the assignment and the answer was #1 +2 n