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Question
Although fluorine is more electronegative than oxygen, but the ability of oxygen to stabilise higher oxidation states exceeds that of fluorine. Why?
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Solution
The electronic configuration of fluorine is \[\ce{1s^2 2s^2 2p^5}\]. Thus it can form only one bond as it has only one unpaired electron. Electronic configuration of oxygen is \[\ce{1s^2 2s^2 2p^6 3s^2 3p^6}\].
It may be mentioned that oxygen also has vacant d-orbitals along with two 3p orbitals containing single electron. Thus, oxygen has greater bond formation capacity. In other words, it has greater ability to stabilize higher oxidation states.
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