Figure 5-8: Uses of Nonvisible Electromagnetic Radiation (a) A mobile phone is actually a radio transmitter and receiver. The wavelengths used are in the range 16 to 36 cm. (b) A microwave oven produces radiation with a wavelength near 10 cm. The water in food absorbs this radiation, thus heating the food. (c) A remote control sends commands to a television using a beam of infrared light. (d) Ultraviolet radiation in moderation gives you a suntan, but in excess can cause sunburn or skin cancer. (e) X-rays can penetrate through soft tissue but not through bone, which makes them useful for medical imaging. (f) Gamma rays destroy cancer cells by breaking their DNA molecules, making them unable to multiply.

(a: Maurizio Gambarini/dpa/Corbis; b: Michael Haegele/Corbis; c: Bill Lush/Taxi/Getty; d: Neil McAllister/Alamy; e: Ted Kinsman/Photo Researchers, Inc.; f: Will and Deni McIntyre/Science Source)