I have a problem with MgO(s). Mg(s) → Mg(g) Heat of sublimation = +148 kj ½O2(g) → O(g) Bond dissociation = +249 kj Mg(g) → Mg2+(g)+ 2e- IE1+IE2= +2201 kj O(g)+2e- → O2- EA= +737 kj look at the EA in peiodic table O(EA= -141 kj). When O charged 2e- it seems to be like F(EA=-328 kj) charged 1e-. it should be - not +. but Why EA of O=+737kj ?