Question: what is the difference between the two isotopes of chlorine?
Answer: All atoms which contain 17 protons are called chlorine atoms. ... An atom of chlorine-35 contains 18 neutrons (17 protons + 18 neutrons = 35 particles in the nucleus) while an atom of chlorine-37 contains 20 neutrons (17 protons + 20 neutrons = 37 particles in the nucleus).