Feel free to modify and personalize this guide by clicking "Customize."
Recall that there are many ways to define acids and bases. What types of acids and bases have you already learned about? What is necessary for a substance to be categorized as one of these acids or bases?
Lewis acids and Lewis bases make up the most general group of what we know to be acids and bases.
As the graphic above shows, all acids and bases are Lewis acids, but not all acids and bases can be categorized as either Brønsted-Lowry or Arrhenius.
A Lewis base is an electron pair donor and a Lewis acid is an electron pair acceptor.
Beware! Note the differences in the definition of Lewis acids and bases versus the Brønsted-Lowry and Arrhenius definitions. Usually the base is the acceptor and the acid is some sort of donor, but when we're talking about electron pairs (as with Lewis acids and bases), the roles are swapped.
For guidance in answering the questions above or for more information, look here.