DrBob222, thank you for your help on my other question.

Question

I found some information that pointed out that the greater the difference in electronegatives, the shorter the bond length.

Here's another question that maybe you can help me with:

For the series of molecules HF, LiH, and LiF, which is the least polar? Which is the most polar? Answer the questions based on the following dipole moments and explain how dipole moments relate to polarity:

HF: 2.17 D
LiH: 5.99 D
LiF: 5.75 D