Why does group 3 have lower first ionization energy than group 2?

[abelkoontz]

ok its like 3am and im feeling stupid.

my book says group 3 has lower ionization energy than group 2 since group 3 electronic configurations are in the p block and the p have higher energy than the s orbitals but if they need high ionization energy if the p orbital is higher in energy, and therefore requires more energy to remove 

wtf im so confused. help 

[kw0573]

Yeah 3 am is not the time to study chemistry. What the book is saying is that the energy difference between p orbitals and very far away from nucleus (ionized) is smaller than that of s (of the same period) and very far away, hence lower ionization energies for group 3. It's like saying if you are on Mount Everest as opposed to in a trench, less energy is required to send you to space (equivalent of ionizing an electron to very far away or the infinite electron shell) I don't know the exact scenario the book is trying to explain, but this idea of comparing differences rather than absolute values shows up very often in almost branch of chemistry. 

Edited December 23, 2016 by kw0573

[abelkoontz]

2 hours ago, kw0573 said:

Yeah 3 am is not the time to study chemistry. What the book is saying is that the energy difference between p orbitals and very far away from nucleus (ionized) is smaller than that of s (of the same period) and very far away, hence lower ionization energies for group 3. It's like saying if you are on Mount Everest as opposed to in a trench, less energy is required to send you to space (equivalent of ionizing an electron to very far away or the infinite electron shell) I don't know the exact scenario the book is trying to explain, but this idea of comparing differences rather than absolute values shows up very often in almost branch of chemistry. 

OHH ok yeah that makes sense hahah thanks