Photography/chemistry paper question

Are you asking aout the darkening that takes place when the light-activated silver chloride is brought into contact with a developing agent such as Metol or hydroquinone, or the darkening that takes place over time due solely to light, such as that which occurs when a piece of enlarging paper left out of the box? While both are due to a conversion of the silver chloride to silver and/or silver oxide, the mechanisms are a bit different. In each case, though, the energy in one or more photons of light are captured by the silver chloride grain and 'sensitize' it to a further chemical action.
OK in my best layman's English, the chemicals cause a form of oxidization...or rusting of the silver. In other words: It causes it to turn black. The more intense the light that strikes the silver, the darker the effect is, BUT it also has to do with the developer. The stronger the developer, the darker the image can become, quicker, and can cause an over develop situation... or simply put... black paper.

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