I looked online and I found silver (Element symbol is Ag)
The element described is silver.
The element with atomic number 47 is Silver (Ag). It is used in photographic film, as well as solar panels, water filtration, X-rays, and disinfectants.
There is no specific collective noun form photographic film, in which case a noun suitable for the context is used, for example a roll of photographic film, a case of photographic film, an archive of photographic film, etc.
The element with the atomic number 47 is silver (Ag), and it is used to make photographic film and paper. But the atomic number determined the answer, not its use.
There is no standard collective noun for photographic film, in which case, a noun suitable for the situation is used; for example, a case of photographic film, a cache of photographic film, a supply of photographic film, etc.
Photographic film was invented in 1889 by George Eastman. Photographic film and paper is made using silver nitrate which is light sensitive.
rhenium
Photographic film is a type of film used in cameras. This film has one side with transparent plastic coating and the other covered with light-reflecting crystals of silver halide.
Uranium is commonly used in the nitrate in photographic toners. and good luck with that crossword puzzle
just because it does without the lens light can not concentrates on the photographic sensitive material such as film or photographic paper
Celluloid
silver