Question

A compound is broken down by chemical means during(1) chromatography (2) distillation (3) electrolysis (4) filtration

Answer 1

1, 2, and 4 are all through physical means. I believe electrolysis is the answer you're looking for :)

Answer 2

(1) Chromatography, (2) Distillation, and (4) Filtration are just three ways of separating mixtures. (3) Electrolysis is the correct answer because it helps break down a compound into ions.
Hope this would help~