BF3 as a lewis acid

[Izzy Ick 4B]

Why is BF₃ considered a Lewis acid? Using the definition of Lewis acid we learned in class how is this the case?

[Anna Nordstrom 1A]

If you draw out the lewis structure for BF3, you will get the Boron in the center with the three Fluorine's coming off of it. All of the Fluorine's have a full valance electron shell but the Boron only has the three Fluorines coming off of it, and therefore only has 6 electrons in its outer shell. This means the Boron is able to accept an electron pair to get a full outer shell, making it a Lewis Acid.