Question

The electronic configuration of four elements are given below arrange these elements in the correct order of their electron affinity
1) 2s2 2p5 3) 3 s2 3p5
2) 2s2 2p4 4) 3 s2 3p4
Select the correct using the code give below
1) 1 < 2 < 3 < 4
2) 2 > 1 > 4 >3
3) 1 < 3 < 4 < 2
4) 3 < 4 < 2 <1

Answer 1

electron affinity depends on configuration of atom, for half fill and full configured atom has less electron affinity.

now come to the point,

1. 2s², $2p^5$

outermost orbit will be completely fill when we add an electron . so, its electron affinity will be very high.

2. 3s², $3p^5$

outermost orbit will be completely fill when we add an electron so, its electron affinity will be very high and greater than option (1), because in option (1) size of atom is too small to add electron so, first some amount of energy is required to add then after energy release.

size of atom of option (4) is greater than size of atom of option (3), so easily an electron can add in option (4) but in case of option (3), some amount of energy is required

so, we can say that electron affinity of 4 > electron affinity of 3

now, arrangement is 2 > 1 > 4 > 3

hence, option (2) is correct.