As F2 has the smallest size and greatest electron density it should be least reactive slso HF should also be least reactive and I2 due to larger size will be easily reacted HI should also be easily reacted... but it is not the case... then what is correct regarding the size and reactivity? HydroHalogenation is in order of HI>HBr>HCl>HI same order should be for halogenation But it is not so..

As F2 has the smallest size and greatest electron density it should be

1.	As F2 has the smallest size and greatest electron density it should be least reactive slso HF should also be least reactive and I2 due to larger size will be easily reacted HI should also be easily reacted... but it is not the case... then what is correct regarding the size and reactivity? HydroHalogenation is in order of HI>HBr>HCl>HI same order should be for halogenation But it is not so..
Answer» As F2 has the smallest size and greatest electron density it should be least reactive slso HF should also be least reactive and I2 due to larger size will be easily reacted HI should also be easily reacted... but it is not the case... then what is correct regarding the size and reactivity? HydroHalogenation is in order of HI>HBr>HCl>HI same order should be for halogenation But it is not so..