How do you figure out how many unshared electrons an element has?

Question

How do you know how many dots to put?

Answer 1

There are different energy levels so put 2 in the first ring, 8 in the second thind and fourth. You won't need to go to the fifth! And about the unshared electrons just see if the atom/element has a charge. If positive then it shares "x" ammount of protons because protons are positive in charge. If negative then vice versa!

Answer 2

http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson38.htm