B because chlorine is a halogen. This means that it already 7 valence electrons and only needs 1 more to have a complete outer shell.
I will solve the question assuming the reaction used as below
1 CH4(g) + 1 H2O(g) ==> 1 CO(g) + 3 H<span>2(g)
In the reaction, CH4 is the reactant and CO is the wanted product. If you look at the coefficient of the substance, for every 1 mol of CH4 react there will be 1 mol of CO produced. So, if you have 7 moles of CH4 the amount of CO produced would be: 7 moles * 1/1= 7 moles of CO</span>
<span>The chemical properties of elements is determined by the electron shell configurations of each element. Different electron shell configuration = different chemical properties. And the number of electrons that an element has is determined by the number of protons the element has in it's nucleus. Iron has 26 protons, so a neutral atom of iron will have 26 electrons, while nickle has 28 protons, therefore when neutral will have 28 electrons. And since they have differing numbers of electrons, their electron shells differ and therefore their chemical properties differ.</span>
