An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contain is? by Sunday | Oct 10 | Chemistry JAMB | 0 comments A. 16 B. 15 C. 46 D. 31 Correct Answer: Option B – 15 Users Also Read These:Chlorine consisting of two isotopes of mass number…What is the mass number of an element if its atom…How many neutrons are present in atom with mass…An isotope has an atomic number of 15 and a mass…An element having the atomic number 17 will resemble…