Hybridisation Doubt: When Does it Take Place and When Not?

[Vatsal Goyal]

There is an example given in my textbook showing the structure of BF₃. In it, they have hybridised the orbitals of B to sp2, but not of F. It's written sp2-p overlapping. Why isn't flourine also hybridised, seeing it has 3 lone pairs and 1 bond pair, it could have sp3 hybridisation? Also, in general when does hybridisation take place and when does it not?

 

[Borek]

Why isn't flourine also hybridised, seeing it has 3 lone pairs and 1 bond pair, it could have sp3 hybridisation?

Would it change the final geometry of the molecule?

 

[Vatsal Goyal]

No, I don't think it would. Is that somehow related to the answer?

 

[Borek]

Then it doesn't matter.

 

[Vatsal Goyal]

Then it doesn't matter.

I don't get it, how would the orbitals be arranged in fluorine then?

 

[Borek]

It doesn't matter for the shape of the molecule - you can assume there is no hybridization and orbitals in fluorine are in their standard one s and three p arrangement.

Please remember hybridization is largely a mathematical concept that helps understand what is going on, but is only an approximation of reality.