Ability of pathogen to adapt to medication and becomes no longer effective.

i just needed an answer plz dont delete im failing so hard dude

Explanation:

answer; /// i believe the correct answer is (reactants);

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds