Question

Name the salts that are used in black and white photography. Give reactions when they are exposed to light. Define the type of chemical reaction taking place.

Answer 1

Silver chloride (Agcl) and Silver bromide (AgBr)

2AgCl+ Sunlight →  2Ag+Cl₂

2AgBr +Sunlight → 2Ag+Br₂ 

Those reactions in which energy is absorbed (in form of heat, light or electricity) to break down the reactants is called decomposition reaction.