An isotope has an atomic number of 15 and a mass number of 31. The number of proton it contains is? by Sunday | Sep 16 | Chemistry JAMB | 0 comments A. 16 B. 15 C. 31 D. 46 Correct Answer: Option B – 15 Users Also Read These:The nucleon number and the proton number of a…Chlorine consisting of two isotope of mass number 35…An isotope has an atomic number of 15 and a mass…An element having the atomic number 17 will resemble…The nucleon number and the proton number of a…