Here are the example question says which of the following halogens will have the most exothermic electron affinity. So remember your halogens are the elements in Group 7A of the periodic table. So if we look at the choices sulfur, neon, nitrogen, acetene and bromine, only two of them exist as halogens and those would be options D&E.
So now we have to think about who has the more exothermic electron affinity which means it's more negative. Remember as we head to the top right corner, our electron affinity increases, meaning it becomes more exothermic. So here bromine is higher up in Group 7A, so bromine would have the more exothermic electron affinity.
Now know it's a little weird. More exothermic really means it's a more negative value. But just remember, when we're talking about greatest electron affinity, we're talking about most exothermic.