Question

Explain the condition of light required for chemical changes.​

Answer 1

Evidence of chemical change

Evidence of a chemical change

Change of odor. Change of color (for example, silver to reddish-brown when iron rusts). Change in temperature or energy, such as the production (exothermic) or loss (endothermic) of heat. ... Light and/or heat given off.

Answer 2

Answer:

Light :

Certain chemical reactions take place with the help of light energy. These are called photochemical reactions.

Example: ${H_2 + Cl_2 → 2HCl}$

${6CO_2 + 6H_2O → C_6H_12O_6}$ (photosynthesis)

Some chemical reactions are also associated with release of light energy:

Example: Mg + O → 2MgO + Light.