Sunscreen contains compounds that absorb ultraviolet light. When sunscreen is applied to skin, it prevents ultraviolet light from reach- ing the skin. The graph that follows shows the absorbance of light as a function of wavelength for two different compounds (2-EHMC and TDSA) common in sunscreen. Absorbance is a measure of the amount of light absorbed by the compound-the higher the absor- bance, the more light is absorbed. Study the graph and answer the questions. 0.6 UV-E UV-A 0.5 0.4- 2-EHMC 0.3 TDSA 0.2- 0.1 290 300 310 320 330 340 350 360 370 380 390 400 Wavelength (nm) Assuming that sunlight produces 3.066 x 10". UV photons and m -s that the skin absorbs one-half of these photons (and reflects the other half), calculate the total UV energy absorbed over 0.42 m of skin that is exposed to sunlight for one hour. Assume that the average wavelength of the UV photons is 330 nm. Absorba nce

Sunscreen contains compounds that absorb ultraviolet light. When sunscreen is applied to skin, it prevents ultraviolet light from reach- ing the skin. The graph that follows shows the absorbance of light as a function of wavelength for two different compounds (2-EHMC and TDSA) common in sunscreen. Absorbance is a measure of the amount of light absorbed by the compound-the higher the absor- bance, the more light is absorbed. Study the graph and answer the questions. 0.6 UV-E UV-A 0.5 0.4- 2-EHMC 0.3 TDSA 0.2- 0.1 290 300 310 320 330 340 350 360 370 380 390 400 Wavelength (nm) Assuming that sunlight produces 3.066 x 10". UV photons and m -s that the skin absorbs one-half of these photons (and reflects the other half), calculate the total UV energy absorbed over 0.42 m of skin that is exposed to sunlight for one hour. Assume that the average wavelength of the UV photons is 330 nm. Absorba nce