[Krystalsnow2013]

1. How does understanding electron configuration help with understanding the trends in IONIZATION ENERGY (especially jagged appearance and drop for group 13)?

2. What is the difference between a POSITIVE and NEGATIVE electron affinity value?

3. How does understanding electron configuration help with understanding the trends in ELECTRON AFFINITY (especially how Groups 2 and 8 have positive values)?

[Borek]

We won't do homework for you. Please read the forum rules, you have to show you efforts at answering the question to receive help.

[Vidya]

electron configuration help with understanding the trends in IONIZATION ENERGY

Check the stability of electron configuration and it is difficult to remove electron from stable configuration.

difference between a POSITIVE and NEGATIVE electron affinity value

Again it is based on stability of electron configuration so like noble gases have positive electron gain enthalpy.

electron configuration help with understanding the trends in ELECTRON AFFINITY (

Again check stability of electron conjurations and from there you can understand the relation in electron affinity and ionization energy.

I hope you know that exactly half filled and fully filled subshells are more stable than partially filled subshells.
Fully filled shells like noble gases are very stable so they show very high IE and positive EA.
2md group is fully filled ns² (subshell) and 15 group is exactly half filled p subshell (ns²np³).