the outer proton heavy is a whole of the proton seawater
sodium_hydroxide is solid. proton_transport is translation_of_ion. outer_nuclear_membrane is lipid_bilayer. tritium is heavy_radioactive_isotope_of_hydrogen. hydrogen_ion is proton. proton_transport is transport. protons is component_of_atoms. heavy_water_nuclear_plant is tangible_thing. proton is rocket.