Light as Electromagnetic Radiation (4D) Practice Test

A pigment in a bacterial photosystem absorbs strongly at 800 nm. When illuminated with 800 nm light, electron transfer is observed; when illuminated with 400 nm light at the same intensity, electron transfer is reduced due to pigment degradation. Constants: $E=hc/\lambda$, $h=6.63\times10^{-34}\ \text{J·s}$, $c=3.00\times10^8\ \text{m/s}$. Which conclusion is most consistent with electromagnetic radiation principles?

A lab compares tissue heating from 10 s exposures to 1064 nm (near-IR) and 532 nm (green) lasers. For the same power (W) delivered to the tissue, temperature rise is similar, but photochemical damage is higher at 532 nm. Constants: $E=hc/\lambda$, $h=6.63\times10^{-34}\ \text{J·s}$, $c=3.00\times10^8\ \text{m/s}$. Which conclusion is most consistent with electromagnetic radiation behavior?