Silver salts play a role in the development of instant photographs because they are photosensitive (I.e. Sensitive to light ) when light hits the photographic film the silver ions in the salt gain electrons and are reduced to silver atoms the pattern of silver atoms results in the picture we see on the photograph
Light also helps in photosynthesis reactions. Green chlorophyll molecules in plants absorb energy from sunlight in order to convert water and carbon dioxide to glucose and oxygen