Electromagnetic Waves Chapter 17

Gamma Rays

Gamma rays carry the largest amount of energy of all EM waves, because they have the shortest wavelength and highest frequencies. Gamma rays penetrate materials very easily. Gamma rays can be focused on tumors to kill cancer cells, but they often kill some healthy cells also.

Infrared Waves

Infrared waves have shorter wavelengths and higher frequencies than microwaves and radio waves, so they carry more energy. Infrared waves given off by the sun are absorbed by your skin. The energy of the waves causes your skin to vibrate faster. You feel the increase vibration as heat. Everything, even you give off infrared waves. The amount of infrared radiation emitted by an object depends on its temperature. Infra means below- so infrared means below red. Used in night vision goggles.

Electromagnetic Waves

It is a wave that can travel through empty space AND matter. They form when an electric charge accelerates. Also known as radiant energy. EM= Electromagnetic

Electromagnetic Spectrum

It is the entire range of EM waves. They are arranged by frequencies and wavelengths.

RADAR

Microwaves are also used in radar.

Microwaves

Microwaves have a shorter wavelength and higher frequency than radio waves, therefore they carry more energy. Food particles vibrate and absorb energy.

Radio Waves

Radio waves have the longest wavelength, lowest frequency, and lowest energy. AM radio waves are longer wavelengths than FM radio waves. AM=Amplitude Modulation FM=Frequency Modulation

TV

Television uses FM radio waves to transmit images and AM radio waves to transmit sound.

The speed of light

The speed of an EM wave in space is 300,00.00 km/s.

Source of EM waves

These are: *The Sun *All matter

Ultraviolet light

Ultraviolet has shorter wavelengths and higher frequencies than visible waves, infrared waves, microwaves, and radio waves therefore the carry more energy. Most of the ultraviolet light from the sun blocked by the atmosphere. It can still travel through clouds, so sunscreen is important everyday. Ultraviolet light can be used to kill bacteria on food, surgical, instruments, and even our lab goggles. Our skin needs some ultraviolet light produce vitamin D, which then helps us absorb calcium. -Overexposure to ultraviolet light can cause: sunburn, skin cancer, eye damage, wrinkles, and premature aging of the skin.

X-rays

X-Rays have shorter wavelengths and higher frequencies than ultraviolet, visible light, infrared, microwaves, and radio waves. They carry a lot of energy and easily penetrate materials, so they are very useful to see bones and teeth. patients receiving X-rays often wear a lead-lined apron to protect the parts of the body that so not need X-Ray exposure.

Visible Light

visible light is the very narrow range of the EM spectrum that humans can see. Humans see the different wavelengths as different colors, The longest wavelength is seen as red and the shortest wavelength is seen as violet. White light is presence of all colors of visible light. RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, AND VIOLET.