How does fluorine's electronegativity compare to the electronegativity of oxygen and chlorine?

 The  electronegativity   of fluorine  compare  to the  electronegativity   of oxygen and chlorine as below

Fluorine  has the highest electronegativity   than oxygen  and  chlorine.

  Explanation

 Generally  the  electronegativity    increase   across the period ( from the left to the right)  and  decreases down  the group.

Fluorine is a smaller atom so when it forms a covalent bond, the shared electrons are closer to the nucleus and there is less shielding, electronegativity of oxygen is greater.

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