Two atoms that are isotopes of one another must have the same number of what?

A. protons

B. neutrons

C. electrons

D. all particles

B

Explanation:

Two atoms which are isotopes of one another must have a different number of neutrons.

Isotopes are defined as atoms of the same element which have the same numbers of protons i. e. atomic number remains the same, but has different numbers of neutrons. It is observed that they have same chemical properties due to the same electronic configuration but physical properties differs.