What is the mass number of an element if its atom contains 10 protons, 10 electrons and 12 neutrons? By: Sunday|Published on: May 13|Categories: Chemistry WAEC| 0 comments A. 32 B. 22 C. 20 D. 10 Correct Answer: Option B B. 22 Users Also Read These:A particle that contains 9 protons; 10 neutrons and…How many protons, neutrons and electrons…The nucleon number and the proton number of a…The nucleon number and the proton number of a…The number of unpaired electrons in an atom of an…SEE ALSO The quantity of electricity required to discharge 1 mole of univalent ion is?