Step-by-step explanation:
Oxygen has an atomic number of 8 with 2 electrons in its innermost shell (s orbital) and 6 remaining electrons in its outermost shell.
The electronic configuration of the oxygen element will therefore be expressed as;
1s²2s²2p⁴
Since we are to find the valence electron configuration of oxygen, this means we are going to consider only electrons in the outermost shell. The outermost shell of oxygen only contains 6electrons. The electronic configuration will be;
2s²2p⁴ (ignoring the innermost electrons)
Comparing with As^B2p^C
we will have;
As^B = 2s²
A = 2, B = 2
2p^C = 2p⁴
p^c = p⁴
C = 4
Hence A = 2, B = 2 and C = 4
The oxygen ion is represented as O₂²⁻. Therefore the charge of an oxygen ion is -2