An element and its isotope only differ in the number of? by Sunday | Nov 3 | Physics JAMB | 0 comments A. protons B. electrons C. ions D. neutrons Correct Answer: Option D – neutrons Users Also Read These:An isotope has an atomic number of 15 and a mass…The nucleon number and the proton number of a…If the relative molecular mass of an element is not…Chlorine consisting of two isotope of mass number 35…The atomic number of an isotope of hydrogen is equal…