Which of the following is closest to the longest wavelength of visible light detectable by the human eye?

• A. 550 nm
• B. 400 nm
• C. 700 nm
• D. 350 nm

Answer: (C)

Verified step by step guidance

1. Understand that visible light is the portion of the electromagnetic spectrum that the human eye can detect, typically ranging from about 400 nm to 700 nm in wavelength.
2. Recall that wavelength and color are inversely related: shorter wavelengths correspond to violet/blue light, and longer wavelengths correspond to red light.
3. Identify that the longest wavelength of visible light corresponds to the red end of the visible spectrum, which is approximately 700 nm.
4. Compare the given options (550 nm, 400 nm, 700 nm, 350 nm) to the known visible spectrum range and determine which is closest to the longest wavelength detectable by the human eye.
5. Conclude that 700 nm is the closest to the longest wavelength of visible light detectable by the human eye.