What is the difference between a Lewis acid or base and a Brønsted Lowry acid or base?

Question

Chemistry Question

Answer 1

A Bronsted Lowry acid is a substance that donates a proton (H+)

A Bronsted Lowry base is a substance that accepts a proton (H+)

A Lewis acid is a substance that accepts a pair of electrons.

A Lewis base is a substance that donates a pair of electrons.

 

A simple example of a Lewis acid/base would be something like 

BF3 + F- ===> BF4-

Here the BF3 accepts the pair of electron from F- and so it a Lewis acid.  The F- donates the electrons and so is the Lewis base.