2 shells because if you do the electronic configuration:
2,7 which adds up to 9
7 stands for the group it in and it also stands for how many electrons are in the outer shell.
the amount of spaces stands for which period its in therefore it in period 2
Explanation:
I don't understand your question....
thank you
a electron behavior is a subatomic particle whose electric i charge and the other one is a molecule and chemical bond that shares electrons