Firstly, silver is not a chemical, it is an elemental metal.
If I am to presume your question relates to film (not paper) and how the latent image is laid down, then my answer is no. I must confess I'm not an expert on the history of photographic processes, but I do believe they all involved silver or silver salts where the creation of permanent images was concerned. The silver halide of today is typically silver chloride, silver bromide or silver iodide based, or a combination of those. I don't believe silver iron is used anymore. There are non-silver based printing processes, but as I mentioned, my assumption precludes these.
I also presume you are not referring to the coupling of dyes with developed silver halides in color film processing. In this case, silver is "substituted" during the color film development process.
Decomposition of silver halides under light irradiation.
Silver is already ametallic chemical element. But so is mercury (chemical element), and it can supposedly be turned into gold, which is another chemical element.
Silver (Ag) has an atomic number of 47 and is used in photography.
There are many elements that play key roles in photography. One is the lighting. Another is the location. The most important though is the subject and how still it is.
it is silver
The molecular formula for silver iodide is AgI.Silver iodide is an inorganic, yellow compound which is used in many things, from silver-based photography to antiseptic.
There are various places where you can find photography tutorials online. Silver Light provides free photography tutorials and an introduction to photography.
Silver nitrate.
Yes
actually not silver chloride but silver bromide AgBr is used in black and white photography as a soft, pale yellow, insoluble salt well known (along with other silver halides for its unusual sensitivity to light. This property has allowed silver halides to become the basis of modern photographic materials. AgBr is widely used in black and white photography film The classic black and white film would be made using silver bromide which is made from silver nitrate. Silver nitrate is a chemical compound with chemical formula AgNO3. This nitrate of silver is not the light sensitive ingredient in photographic film .
Finely powdered silver is black in color (which is what made it useful for black and white photography - now largely superseded by digital photography).
Yes - silver does react and that is why there are quite a few compounds of silver. It is used in photography for example.