Chemistry of Photographs

4. Compounds used in silver halide photographic processes such as hydroquinone, diaminophenol or amidol.
6. The type of image produced by the photochemical reaction of silver halides is amplified in the development process.
9. This sodium salt is used to fix photographic images.
10. Type of compound that can cause photographs to fade. Sources include untreated wood, paints and varnishes.
11. This colour of dye is added to coloured film to make it sensitive to green light.
12. Sensitizing agents are usually made of compounds containing this element.
13. This photographic process required cellulose nitrate, alcohol, ether and halide salts on glass.
14. Dichromate is reduced to this oxidation state in the gum bichromate process.
17. Burning of fossil fuels creates these gases that cause photographs to fade by chemical reactions with the silver image.
19. Element used in vapour form to produce daguerreotypes.
20. When storing photographs, keeps this value low to slow down deterioration, silver oxidation and shifting and fading of colour dyes.

1. The most light-sensitive silver halide.
2. A silver salt used in photography.
3. This layer prevents light from reflecting back into the emulsion layer and causing ghosting.
5. Photographic tone formed from the reaction of silver with thiosulfate in acid solution
7. A reaction catalyzed by light.
8. A compound in the protective layer of photographic film that is formed from the partial hydrolysis of collagen.
10. The polymer used as film backing from the 1960s to the present day.
15. The type of reaction that converts silver ions to silver metal.
16. This type of defect in ionic crystals is required for the photosensitivity of silver halides.
18. To produce cyanotypes, complexes containing this metal are required.