We are asked to choose the element with the more negative (more exothermic) electron affinity between B or S.
Recall that electron affinity is the energy change from the addition of 1 e– to a gaseous element/ion.
It is represented by this chemical equation:
Atom(g) + e– → Ion–(g), ΔE = –E.A.
The trend for electron affinity is as follows: it increases from left to right and decreases down a period in the periodic table. The given elements are:
Choose the element with the more negative (more exothermic) electron affinity from each of the following pairs.
B or S