Question

Arrange elements of period 2 in increasing order of electron affinity

Answer 1

        I think it would be Si<P<Li<Cl:

It increases across the period bc each element furtger to the rigjt has more protons for the same amount of shielding therefore the valence electrons are more attracted to the nucleus. There are exceptions but only group 3 and 6. Li is higher than Si and P bc it's in period 2 so has the least shielding of them all but lower than Cl because it has relatively few protons (3). However I could be wrong; Li is hard for me to place honestly in this list but without Li it is definately Si<P<Cl

Electron affinity:

                              The first is always exothermic but in terms of increasingly exothermic I'd go with the same pattern

Si<P<Li<Cl

Because Li is going to have a lot less shielding than the others and therefore larger nuclear attraction to the electrons therefore it would be more exothermic. Than Si and P maybe. But Cl would be more exothermic bc although the shielding is increased there is just such a greater number of protons that the attraction is greater between Cl atoms and electrons.

Now I could be wrong about thr pattern when it comes to placing Li because it is abit harder to place without fully thinking about it more thoroughly.