Question

State briefly the similarities and differences between the theories of Arrhenius and Bronsted-Lowry

Answer 1

My answer to the question above is not the best example but I hope it will help you. The Arrhenius model says that acids always contain H+ and that bases always contain OH-. 
The Bronsted-Lowry model thinks of acids as being proton donors and proton acceptors, so bases no longer need to contain OH-, and acids donate a proton to water forming H3O+. 
Lewis acids are electron pair acceptors, and Lewis bases are electron pair donors. For instance, H+ + OH- => H20. H+ has no electrons, so when it bonds to the Oxygen, it gains an electron pair. OH- "loses" an electron pair.