Question

The formation of the oxide ion $O_{(g)}^{2-}$ requires first an exothermic and then an endothermic step as shown below :
O(g) + e⁻ = O⁻(g) $\Delta H^0$= -142 kJmol⁻¹
O- (g) + e⁻ = O²⁻(g) $\Delta H^0$= 844 kJmol⁻¹
This is because
(a) O⁻ ion will tend to resist the addition of another electron
(b) Oxygen has high electron affinity
(c) Oxygen is more elecronegative
(d) O⁻ ion has comparatively larger size than oxygen atom

Answer 1

${\huge {\mathfrak {Answer :-}}}$

➡️ Option (A)

That's it..

Answer 2

Option A is correct ✔✔

Thanks