- Slides: 13
Electromagnetic Waves � All electromagnetic waves are transverse waves. � They do not require a medium to travel through. � All types of electromagnetic radiation (ER) travel at the speed of light (300, 000 m/s in a vacuum).
Electromagnetic Spectrum � This is a chart of all of the ER. � The types of ER are ordered based on wavelength and frequency. � As frequency increases; wavelength decreases as vice versa. � An increase in frequency also correlates with an increase in temperature and the amount of energy the wave has.
Radio Waves � Longest wavelength (10 m to 30 cm) � Lowest Frequency ( < 10 billion Hz or 10 gigahertz (GHz) � Used for AM and FM radio, TV, and RADAR
Microwaves �A little shorter wavelengths (30 cm to 1 mm) � A little higher frequency (10 GHz to 300 GHz or 0. 3 terahertz (THz)) � Used to heat up the water in foods to cook them � Also used in all cell phone communications.
Infrared Waves � Wavelength from 1 mm to 0. 00076 mm or 760 nanometers (nm) � Frequency from 0. 3 THz to 390 THz � Waves picked up by night vision goggles so we can see in the dark � Used in heaters and toasters.
Visible Light � Wavelength from 760 nm (red) to 380 nm (violet) � Frequency from 390 THz (red) to 790 THz (violet) � Includes all of the colors that we can see with just our eyes.
Ultraviolet Waves � Wavelength from 380 nm to 8 nm � Frequency from 790 THz to 34, 000 THz � Gives us sunburn (and can cause skin cancer) � Used in tanning beds. � Also used to sterilize medical equipment because it kills microorganisms.
X-Rays � Wavelength from 8 nm to 0. 006 nm (or 0. 06 Angstrom Å) � Frequency from 34, 000 THz to 50, 000 THz � Easily travels through skin but not more solid things like bone. Therefore, they’re great for use in the medical field. � Long exposure can cause cancer.
Gamma Rays � Wavelength from 0. 06 Å and smaller. � Frequency from 50, 000 THz and above. � Used to kill cancer cells � Goes easily through the entire body, including bones, so it can be used to image the interior of the body. � Can also cause cancer.