Why does boron trifluoride behave as a Lewis acid?

Why does BF_3 behave as a Lewis acid?

When BF_3 is treated with LiH at 450 K, a hydride of borbon is formed. Boron compounds behave as Lewis acids. Why?

What are electron deficient hydrides? Whether they behave as Lewis acids or Lewis bases? Why?

Borax, orthoboric acid and diborane are some useful compounds of boron Boric acid Is not a protonic acid but acts as a Lewis acid. Justify.

Diborane is an important hydride of Boron a. During a class room discussion, a student argues that there is a covalent bond between boron atoms in diborane. What is your opinion. Give justification. b. Boron halides can act as Lewis acids. Give reason. c. Arrange the following Lewis acids in the increasing order of acidic strength. Substantiate your answer? 'BF_3 BCl_3, BBr_3'

Why does BF_3' act as a lewis acid?