Question

Black and white photography uses:
(A) Decomposition of silver chloride
(B) Decomposition of silver bromide
(C) Both
(D) None of these

Answer 1

Hint: In the process of photography, it is important that the chemical used is photo- sensitive. Compounds of silver metal generally halides possess this property. To answer this question, you must recall the process and functioning of the traditionally used black and white photography.

Complete step by step solution:
The ability of photography was harnessed by photographers in the 19th century by the pioneering use of a coating of halides of silver, i.e. molecules of silver metal and halide gases present together in an emulsion of gelatin in a plastic or glass beaker. Even now, the process of photography uses the same basic reaction which was used back in the olden days.
Silver bromide is known for its unusual photo- sensitivity and this property has caused it to become the basis of photographic materials in modern times. In presence of light, silver bromide undergoes decomposition giving silver which is grey in colour.
Thus, the correct answer is B.

Note:
From the colour schemes formed by certain types of films and by observing the trends in the digital processing it is evident that the colour of the resultant photograph represents a specific era. The lights and shadows are often accentuated by the lack of colour in a photograph. Hence, the dramatic shadows and backlit subjects are quickly brought into the attention of the audience in black and white photographs. As a result, black and white photographs are preferred to date by many professional and fine art photographers because of their tendency to distance the subject from reality.