Which color of light has a wavelength longer than ultraviolet light?

The correct choice is infrared because it falls within the electromagnetic spectrum at wavelengths longer than ultraviolet light. Ultraviolet (UV) light has wavelengths ranging from about 10 nm to 400 nm, while infrared light begins just after the visible spectrum, typically starting around 700 nm and extending to about 1 mm. This positioning means that infrared light has significantly longer wavelengths than ultraviolet light.

In contrast, red, blue, and green light belong to the visible portion of the spectrum, with red light having the longest wavelength among the three but still shorter than infrared. Red light ranges from about 620 nm to 750 nm, blue light ranges from about 450 nm to 495 nm, and green light is between approximately 495 nm and 570 nm. Therefore, infrared light is the only color listed that has a wavelength longer than that of ultraviolet light.