Answer:
The correct answer is 4 electrons.
Explanation:
Reduction reaction is defined as chemical reaction in which element gains electrons and it get reduced. Also oxidation state of that element also deceases.
[tex]O_2+e^-\rightarrow 2O^{2-}[/tex]
Charge on both sides should be balanced so for that write 4 as a coefficient of en electron in an above reaction.By this the charge on booth sides becomes (4-).
[tex]O_2+4e^-\rightarrow 2O^{2-}[/tex]
1 mole of oxygen gas gets reduced by 4 electrons into 2 moles of oxygen ions.
