Given that

(1) the first and second electron affinities of sulfur are–0.332 aJ and 0.980 aJ,

(2) the ionic radii of Zn2 and S2– are 74 pm and 184 pm, andthat

(3) Zn (g) -> Zn 2+ (g) + 2e- E= 4.38aJ

calculate the energy change for this reaction (per formula unitof ZnS).

Zn (g) + S (g) --> ZnS (g)

Erxn = ???? aJ