Final answer:
The oxygen peroxide ion (O^-2^2) has 8 valence electrons.
Step-by-step explanation:
Oxygen peroxide ion (O-2)2 has a total of 8 valence electrons. Each oxygen atom has 6 valence electrons, and since there are two oxygen atoms, we have 6 x 2 = 12 valence electrons. However, the ion has a -2 charge, so we need to subtract 2 electrons, giving us a total of 10 valence electrons. Therefore, the correct answer is c) 8 valence electrons.