BF3 has zero dipole moment as it is symmetrical in nature. H2O has maximum dipole moment as it possess two lone pair of electrons. Between NH3 and NF3,NH3 has greater dipole moment though in NH3 and NF3, both N possesses one lone pair of electrons. This is beacuse in case of NH3, the net N−H bond dipole is in the same direction as the direction of dipole of lone pair. But in case of NF3, the direction of net dipole moment of three −N−F bonds is opposite to that of the dipole moment of the lone pair. Thus, the correct of dipole moment is 