Which of the following is a pure substance? a. chocolate milk b. orange juice c. seawater d. hydrogen peroxide (h2o2)

A pure substance is defined as a matter having definite and constant composition all throughout a sample. It is held by chemical bonds therefore only chemical processes can be used to break it. I think the correct answer among the choices listed is option D.

D. Hydrogen peroxide (H2O2)

Processes above and be sure to mention the movement of electrons and energy as the carbon atom moves from one reaction to another.