In black-and-white photography, a photon energy of about 4.00 10 19 J is needed to bring about the changes in the silver compounds used in the film.

× 10−19

J is needed to bring about the changes in the silver compounds used in the film. Explain why a red light used in a darkroom does not affect the film during developing.

The minimum or maximum

(select)minimummaximum

energy of a red-light photon is much

more or less?

(select)moreless

than the energy

required to bring about the changes in the silver compounds.