Answer: a change in energy state occurs. The answer is dark or opaque - not able to be seen through.
Explanation:
The absorption of light makes an object dark or opaque to the wavelengths or colors of the incoming wave: Wood is opaque to visible light. Some materials are opaque to some wavelengths of light, but transparent to others. Glass and water are opaque to ultraviolet light, but transparent to visible light.
When oxygen is absent, anaerobic respiration occurs ('an' means without).