Photochemical effects are associated with wavelengths shorter than which value?

Photochemical effects are associated with wavelengths shorter than which value?

• A. Greater than 550 nm
• B. Exactly 550 nm
• C. Less than 550 nm
• D. 450 nm

Answer: (C)

Photochemical effects occur when photons carry enough energy to drive chemical changes, and photon energy increases as wavelength decreases (E = hc/λ). Around 550 nm lies the boundary where light has sufficient energy to influence chemical bonds; therefore, wavelengths shorter than about 550 nm are associated with photochemical effects. Wavelengths longer than 550 nm have lower energy and are less likely to trigger these reactions. A fixed value like 450 nm is too specific—photochemistry is tied to the threshold at 550 nm, with all shorter wavelengths potentially capable of producing such effects.

Photochemical effects occur when photons carry enough energy to drive chemical changes, and photon energy increases as wavelength decreases (E = hc/λ). Around 550 nm lies the boundary where light has sufficient energy to influence chemical bonds; therefore, wavelengths shorter than about 550 nm are associated with photochemical effects. Wavelengths longer than 550 nm have lower energy and are less likely to trigger these reactions. A fixed value like 450 nm is too specific—photochemistry is tied to the threshold at 550 nm, with all shorter wavelengths potentially capable of producing such effects.