How many protons does 40//20Ca contain? By: Sunday|Published on: May 9|Categories: Chemistry WAEC| 0 comments A. 20 B. 30 C. 40 D. 60 Correct Answer: Option A A. 20 Users Also Read These:Protons and electrons are called fundamental…The number of protons in an element increased by one…A metallic ion Z2+ with an inert gas structure…What is the mass number of an element having 20…A particle that contains 9 protons; 10 neutrons and…SEE ALSO C(s) + H2O(g) → H2(g) + CO2(g) ΔG for the reaction above at 1300k is -43KJ. What becomes of this reaction at this temperature?