uhm.... i think it has something to do with the subshells etc... like if all the electrons having positive half spins are filled the atom is much more stable...nit said:This wasn't strictly a story about our chem teacher, but we had a substitute one day last year who the school was trying out as she'd applied for a job at our school...
She was teaching us about trends for the ionization energies across a period, and glossed over the decrease in IE going from Mg to Al and also N to O...Our class being loaded with smart guys asked her why the trend failed between Mg and Al, and she replied that she didn't know and that we should look it up...
We got to N and O, and asked her the same question again, and she replied again that she didn't know. At the end of the period, we asked her the exact same question one final time, and the head of the department, who'd been marking her, had to step in...
So that's my story of incompetent chem teachers and how we as a class basically destroyed one chem teacher's career
but then again.. tis not in syllabus... so yea, i agree with eagle... that's a bit mean... =p