"Want" is a word you should try to avoid when talking about atoms. Oxygen reacts to get a full outer shell of 8.
An oxygen atom has six (6) electrons in its outer shell.
Oxygen: 6 electrons
8
Oxygen has 6 valence electrons. These are in the outer orbit.
2
2
The word "valance" is used to describe electrons in the outer-most energy level of an atom. Oxygen has six valance electrons.
6
An electrically neutral oxygen atom has eight electrons, one for each proton in its nucleus. Two electrons are in the inner shell and six are in the outer shell.
0. All electrons will pair if there is an even number
Oxygen is a non metal element. There are 8 electrons in a single atom.
A neutral atom of oxygen has 6 electrons in it's most outer orbit. Generally, if you count horizontally from left-to-right on the periodic table, you get the number of electrons in its' most outer orbit. You start every row with 1, of course. :) Hope that helps!