Question

#1: Which type of substance is an electron-pair donor?

A. Arrhenius acid

B. Brønsted-Lowry base

C. Brønsted-Lowry acid

D. Lewis base

***I'm not sure on this one.. :( what do you think? @aaronq :)

Answer 1

Lewis Base

Explanation: just took the test; picture below:)

Answer 2

Answer is: D. Lewis base.
Lewis acid is a chemical element, molecule or ion that contains an empty orbital which is capable of accepting an electron pair from a Lewis base. A Lewis base is element, molecule or ion that has a filled orbital and has electron pair which is not involved in bonding and can give it to Lewis acid. Lewis base is for example ammonia (NH3).