Question

Exposure of silver bromide to sunlight for a long duration turns grey due to:
A. the formation of silver by decomposition of silver bromide
B sublimation of silver bromide
C. decomposition of bromine gas from silver bromide
D. oxidation of silver bromide

Answer 1

Hint:All silver halides are light sensitive as they belong to the same group they possess the same chemical characteristics. On exposure with light, they show decomposition reactions.

Complete step by step answer:To obtain a good picture from photography, chlorine chemistry is generally applied. The chlorine chemistry plays a very important role in the formation of film photography.
The silver chloride (AgCl), silver bromide (AgBr), and silver iodide (AgI) are the three important silver halides used in photography technique. The halides element chlorine, bromine and iodide belong to the same group and possess the same chemical characteristics.
The silver halides are light sensitive which is key for photography. The tiny crystals of all three silver halides are used to form a photographic film. When the silver halides are exposed to light they show decomposition reaction to form silver cation and halide anion.
The decomposition reaction of silver bromide is shown below.
$AgBr \to A{g^ + } + B{r^ - }$
The silver bromide decomposes into silver ion and bromide ion. The silver ion has one electron less. Therefore it is positive in charge and bromide ion has one extra electron therefore it is negative in charge.
The white colour silver bromide changes its color to grey due to the formation of silver ions.
Therefore, the correct option is A.

Note: When a film containing silver bromide is exposed to light, the extra electron present in the chloride ion is ejected and then the image is captured by the silver ions.