A substance breaks down into its simpler components in by the passage of sunlight.
Examples
1. Photolytic decomposition of silver nitrate: Silver nitrate decomposes in the presence of sunlight to give silver, nitrogen dioxide and oxygen.
The balanced equation for the reaction is,
2AgNO3Sunlight−−−−−→2Ag+2NO2+O2
2. Photolytic decomposition of silver bromide: silver bromide decomposes in the presence of sunlight to give silver and bromine.
The balanced equation for the reaction is,
2AgBrSunlight−−−−−→2Ag+Br2