a substance capable of bringing about the reduction of another substance as it itself is oxidized; used in photography to lessen the density of a negative or print by oxidizing some of the loose silver

any compound that does not contain carbon

an inorganic compound with the formula NaBH4.

a tetrahydroborate and known in organic synthesis as a reducing agent for esters.

a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder

a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe