You should always study. you can be above your class. thats what i do.. search google for ur course. they can tell u some key points for it. u should even study what you know and want to know as well.
They had fresher breathe because their breathe may have been bad before.
Excuse me not giving an explanation; I haven't even learned chemistry before. I usually give explanations for math/english.
I think it would be for flourine: 7
aluminum: 8
can't help with the rest...
sorry!
