What are the divisions of white light according to the electromagnetic spectrum? Which are the two most efficient colors for photosynthesis?

Answer 1

When white light is passed through an object such as a prism, the light is broken down into visible light which consists of all the colors of the rainbow from red to violet, and with wavelengths ranging from 409 to 709 nanometers.

The two most efficient colors or wavelengths for photosynthesis would be red and blue where the wavelengths contain enough energy to excite the chlorophyll electrons, driving photosynthesis.