Question

Consider oxygen, which has an atomic number of 8 and an atomic mass of 16. how many valence electrons does it have?a. 2

Answer 1

The maximum size of the inner shells are 2,8,18...
Valence electrons are found in the outermost shell of an atom (most of the time).
So the valence electrons of oxygen lies in the second shell, which has 8-2=6 valence electrons.