Which color of light has the lowest energy?

In the context of electromagnetic radiation, the energy of light is inversely proportional to its wavelength. This means that longer wavelengths correspond to lower energy levels, while shorter wavelengths equate to higher energy levels.

Red light has the longest wavelength among the options listed, typically around 620 to 750 nanometers. Since it is on the lower end of the visible spectrum, it carries less energy compared to other colors like blue, green, and yellow, which have shorter wavelengths.

Thus, red light is categorized as having the lowest energy among the provided choices. In contrast, blue light has a much shorter wavelength and higher energy, while yellow and green fall somewhere in between red and blue in terms of wavelength and energy levels. Understanding this relationship between wavelength and energy helps clarify why red light is the correct answer regarding having the lowest energy.