Question

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

Answer 1

The valence electron of an atom has the highest energy level and is found on the outermost energy level. It is also the group number

Answer 2

It's how many are in the element's outer layer. The layers go: 2, 8, then 8.

Ex-6 electrons. 1 layer is 2, the next layer has 4 left. If that layer holds 8, you can do 8-4 and it has 4 valence electrons.

Ex-10 electrons. 1 layer is 2, the next layer has 0 left. It has 8 valence electrons because the outermost layer is full with 8.

ex-11 electrons. 1 layer is 2, the next layer is full as well. 2+8=10; it has 1 left. So that element has only one valence electron.