Question

Photographic plates and films have an essential ingredient of

• A. silver nitrate
• B. silver bromide
• C. sodium chloride
• D. oleic acid

Answer 1

The Correct Option is B

Photographic plates and films primarily depend on a chemical reaction involving a light-sensitive material. The essential ingredient that makes these materials sensitive to light is silver bromide (AgBr).

1. Light Sensitivity: Silver bromide is sensitive to light exposure. When the photographic plate or film is exposed to light, a photochemical reaction occurs where the silver bromide decomposes to form metallic silver and bromine.
2. Image Development: The metallic silver appears as a dark deposit that forms the basis of the photographic image. Areas exposed to more light have more silver reduced, resulting in darker areas on the photographic image.
3. Comparison with Other Options:
   • Silver Nitrate: Although important in photography, it is not used directly in film or plates for image formation. It is often used in the initial preparation of silver bromide.
   • Sodium Chloride: This compound is not light-sensitive and has no direct role in photographic plates or films.
   • Oleic Acid: This is an organic compound with no application in the process of photographic imaging.

Thus, the correct answer is silver bromide, which effectively captures light to create photographic images through chemical reactions.