[abhineet]

Which is more nucleophilic:
iodide(I^-) or fluoride(F^-)?

method-1: F^- is more electronegative and have smaller size than I^-, hence, F^- is more nucleophilic. However, in protic polar solvent due to solvation (strong hydrogen bonding, like in water) F^-, being smaller in size, becomes less reactive than I^-.

method-2: I^- shows more polarisation, therefore, causes more distortion of electrons and hence is more reactive and stronger nucleophile than F^-.

Which method appropriately compares the nucleophilicity of the above ions?
PLEASE TELL THE SOURCE FROM WHERE YOU GET THE ANSWER?