Question

All three of the boron-fluorine single bonds in bf3 are polar. in which direction should the polarity arrows point?

Answer 1

The direction of polarity arrow should be from B atom to F atom

Step-by-step explanation:

F atom has higher electronegativity than B atom.

Therefore the bonding electron between B and F atom will be polarized and become more concentrated towards F atom. Because F atom pulls bonding electrons towards itself more due to it's higher electronegativity.

Hence F atom gets a partial negative charge and B atom gets a partial positive charge.

The polarity arrows are generally pointed from positively charged center to negatively charged center.

So, the direction of polarity arrow should be from B atom to F atom.

Please find the picture below.

Answer 2

The choices are as follows:

-to the right
-to the left
-toward the central Boron atom
-away from the central Boron atom

Fluorine is more electronegative than boron. This means that in the shared electron bond (polar covalent), it draws the shared electrons closer to itself than boron can. Therefore, the polarity arrows point away from the central boron atom.