I thought we find out whether a compound is ionic via EN difference. The EN difference between RbF is larger than NaF... The correct answer is NaF, but I am not sure why.
Hey Jeremy! Are you sure that your textbook says that the correct answer is NaF? According to the electronegativity values, the higher difference is between Rb and F, making that bond more ionic. Please double check and let us know. Thanks!
Okay Jeremy, this might be why. Try using Lattice Energy to explain the ionic bond strength. Charge A x Charge B / period # + period #
Larger lattice energy means stronger ionic bond. Here, NaF is going to have a stronger ionic bond that RbF because of the period # that Na is in. That's why NaF is more ionic. Hope this makes sense!