The total number of valence electrons in a peroxide ion,O₂^2-,is A)2. B)12. C)14. D)13. E)15.

Question

Quizplus · Accepted Answer

To find the total number of valence electrons, we add the valence electrons of each individual atom and then subtract the charge of the ion. 
Oxygen has 6 valence electrons and there are two oxygen atoms in the peroxide ion, so total valence electrons from oxygen atoms are 2 x 6 = 12. 
The single sulfur atom has 6 valence electrons and the single phosphorus atom has 5, so total valence electrons from sulfur and phosphorus atoms are 6+5 = 11. 
Adding these all up gives 12+11 = 23 valence electrons. 
Finally, we must subtract the -2 charge of the peroxide ion, giving us a total of 23-2 = 21 valence electrons. 
Therefore, the correct answer is C (14).

The Total Number of Valence Electrons in a Peroxide Ion,O22-,is

The Total Number of Valence Electrons in a Peroxide Ion,O₂^2-,is