Final answer:
The oxygen peroxide ion (O2^2-) has a total of 14 valence electrons; 12 from the two oxygen atoms and an additional 2 electrons due to the 2- charge.
Step-by-step explanation:
The oxygen peroxide ion, often represented as O22-, contains a total of 14 valence electrons. Each oxygen atom normally has 6 valence electrons, summing up to 12 for two oxygen atoms. The ion carries an extra 2 electrons due to its 2- charge, bringing the total to 14 valence electrons.