Oxygen has first electron gain enthalpy exothermic while second is endothermic still a large number of ionic oxides are formed. Why?

Oxygen has first electron gain enthalpy exothermic while second is end

1.	Oxygen has first electron gain enthalpy exothermic while second is endothermic still a large number of ionic oxides are formed. Why?
Answer» due to octat rule which is made on the BASIS of stability. In CASE of 1st ELECTRON gain enthalpy it forms O- which is LESS stable then OIn case of 2nd EG enthalpy it forms O2- which is more stable then O- and OIt forms large NUMBER of ionic states but it depends upon its environment that which one will form the compound.