Question

Chemical reactions take place by the action of light energy are called ______________.

Answer 1

• Some chemical reactions take place in the presence of light, such reactions are called photochemical reactions.
• Example - Decomposition of silver chloride in the presence of light is a chemical reaction.

$\underset{\mathrm{Silver}\mathrm{chloride}}{2\mathrm{AgCl}\left(\mathrm{s}\right)}\stackrel{\mathrm{Heat}}{\to }\underset{\mathrm{Silver}}{2\mathrm{Ag}}\left(\mathrm{s}\right)+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}$

Thus, chemical reactions that take place by the action of light energy are called photochemical reactions.