Answer the following question given this paragraph: 

29.3 Photon Energies and the Electromagnetic Spectrum 11. Why are UV, x rays, and γ rays called ionizing radiation? 12. How can treating food with ionizing radiation help keep it from spoiling? UV is not very penetrating. What else could be used? 13. Some television tubes are CRTs. They use an approximately 30-kV accelerating potential to send electrons to the screen, where the electrons stimulate phosphors to emit the light that forms the pictures we watch. Would you expect x rays also to be created? 14. Tanning salons use “safe” UV with a longer wavelength than some of the UV in sunlight. This “safe” UV has enough photon energy to trigger the tanning mechanism. Is it likely to be able to cause cell damage and induce cancer with prolonged exposure? 15. Your pupils dilate when visible light intensity is reduced. Does wearing sunglasses that lack UV blockers increase or decrease the UV hazard to your eyes? Explain. One could feel heat transfer in the form of infrared radiation from a large nuclear bomb detonated in the atmosphere 75 km from you. However, none of the profusely emitted x rays or γ rays reaches you. Explain. Can a single microwave photon cause cell damage? Explain. In an x-ray tube, the maximum photon energy is given by.


Q: Tanning salons claim to use a “safe” form of what light, with a longer wavelength than that in sunlight?

 Choices:

- infrared

- microwave

- X rays

- uv (ultraviolet)

A:
uv (ultraviolet)
