An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contain is? By: Sunday|Published on: Oct 10|Categories: 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…The number of electrons in the valence shell of an…The atomic number of an isotope of hydrogen is equal…The atomic number of chlorine is 17. What is the…How many neutrons are present in atom with mass…SEE ALSO When sodium trioxocarbonate (IV) decahydrate loses its water of crystallization to the atmosphere, the process is?