# Why are acids and bases are defined as both donors and acceptors of species in the acid-base theories? [closed]

So, a Brønsted-Lowry acid is a proton donor, and a Brønsted-Lowry base is a proton acceptor. On the other hand, a Lewis acid is an electron pair acceptor, and a Lewis base is an electron pair donor.

Why is it that in these acid-base theories, acids and bases are defined as both donors and acceptors of species? Or is there a part of acid-base theory I don't quite understand?

## closed as unclear what you're asking by Gaurang Tandon, airhuff, Tyberius, Todd Minehardt, MithoronMar 16 '18 at 16:17

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• I honestly don't understand your question. How else do you want acids or bases to be defined as? Some ions will always be donated into the solution, and some will always be accepted from it. What other way is there for acids or bases to function? – Gaurang Tandon Mar 16 '18 at 2:39

Basically, proton is a $H^+$ ion and we all know from our simple understanding that compounds that give $H^+$ or proton are acids and those that accept $H^+$ or proton are bases.