All halogens are stable so they have 8 electrons in their last shell
All the objects are formed from the gas and dust orbitting the sun
The film which you called it is photographic film and it is strip like sheet and it's surface is clrear and transparent plastic which is coated on
two sided one side is with gelatin emulsion consists microscopic small light-sensor which is actually very sensitive in nature silver halides crystals. The size shape and other characters of the crystals gives the sensitivity,contrast of different colors combination ,and resolution of the films.