Ultraviolet radiation is more damaging to skin than visible light because ultraviolet photons
- A. travel faster
- B. have a longer wavelength
- C. carry more energy, enough to break chemical bonds in DNA
- D. are more numerous in sunlight
Explanation
Photon energy is proportional to frequency, so the shorter wavelength ultraviolet carries enough energy per photon to damage the bonds in biological molecules, which is why it causes sunburn and raises skin cancer risk. Visible photons simply cannot deliver that much energy however intense the beam. All electromagnetic waves travel at the same speed, so speed is not the difference.