Editing Quinone (section)

=== Photography ===
A commercial application of quinones is in [[Monochrome photography|black-and-white photography]]. Black-and-white film is covered with an emulsion containing silver bromide or silver iodide crystals, which exposure to light activates. Hydroquinone is used to reduce the activated silver ions to metallic silver. During this process, hydroquinone is oxidized to quinone. All silver halide not activated by light or reduced by hydroquinone is removed, leaving a negative by deposited silver where the film had been struck by light.<ref>{{Cite book |last1=Brown |first1=William Henry |url=https://www.worldcat.org/oclc/974377227 |title=Organic chemistry |last2=Iverson |first2=Brent L. |last3=Anslyn |first3=Eric V. |last4=Foote |first4=Christopher S. |date=2018 |publisher=Cengage Learning |isbn=978-1-305-58035-0 |edition=8th |location=Boston, MA |oclc=974377227}}</ref>