Visible Spectrum Wavelength Order

Steps:

• Recall that visible light wavelengths increase from violet/blue (shortest, ~400-450 nm) to red (longest, ~620-700 nm).
• Identify color positions: blue (~450 nm), green (~510-550 nm), yellow (~570-590 nm), red (~620-700 nm).
• Compare sequences to this order for increasing wavelength.
• Select the option that lists colors from shortest to longest wavelength.

Why A is correct:

• It follows the electromagnetic spectrum order, where wavelength increases progressively from blue to red.

Why the others are wrong:

• B incorrectly places red before yellow, but red has a longer wavelength than yellow.
• C starts with green (mid-range) and ends with blue (shortest), reversing the order.
• D lists colors in decreasing wavelength order, opposite of increasing.

Final answer: A