NY Chemistry Regents Jan 2023
51 Explain, in terms of neutrons and protons, why P-32 and P-31 are different isotopes of phosphorus.
Solution: Isotopes are atoms of the same element with a different mass. P-32 and P-31 are different isotopes of phosphorus because they have the same number of protons (15) but different number of neutrons.
Ps: Whenever a question asks us to explain in terms of something, we must use those words in our explanation. Since the question asked to explain in terms of neutrons and protons, that is what we had to use in our explanation.