4.3 Reading Check page#160

What are three wavelengths that are shorter than visible light?
ultraviolet waves, X rays, and gamma rays.
What are three uses of ultraviolet waves?
Ultraviolet radiation striking your skin enables your body to make vitamin D, which you need for healthy bones and teeth. Fluorescent materials absorb ultraviolet waves and emit the energy as
visible light. Another useful property of ultraviolet
waves is their ability to kill bacteria in food,
water, and medical supplies.
What can result from overexposure to ultraviolet waves?
sunburns and skin cancers, and damage to the surface of the eye.
What are three uses of X rays?
Doctors and dentists use low doses of X rays to form images of internal organs, bones, and teeth. airport security personnel using X-ray screening
devices to examine the contents of luggage. X rays can also be used to inspect for cracks inside high performance jet engines without taking the engine apart, and to photograph the inside of machines.
What can gamma rays be used for?
Focussed bursts of gamma rays are used in radiation therapy to kill cancer cells.