The typical silver salt used in ordinary photographic films is silver bromide, AgBr. The minimum amount of energy needed to initiate the chemical process of dissociation of a AgBr molecule is about 4.00×10−19 J . What is the wavelength λmax that a photon may have to be able to initiate the dissociation of a AgBr molecule?

4.95×10^-7 m

Explanation:

E= hc/λmax

λmax= hc/E

Where :

h= 6.6×10^-34 Js

c= 3×10^8ms-1

E= 4.00×10−19 J

λmax=6.6×10^-34 × 3×10^8/ 4.00×10^-19

λmax=4.95×10^-7 m

Note:

h= planks constant

c= speed of light

E= energy of the photon

λmax= maximum wavelength of the photon.

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