Electromagnetic Radiation http://www.jessb.org 8th Grade      B. Burel & R. Lee

EM Waves Electromagnetic waves are actually made up of 2 parts: an electric force field and a magnetic force field. That’s where the name electo…magnetic comes from! An electromagnetic wave is produced by vibrating electrical and magnetic charges. In fact, all waves are produced by something vibrating.

Waves in space? Most waves, like sound waves or oceans waves must have a medium (some form of matter) through which they travel. However, electromagnetic waves can travel with or without a medium. This allows EM waves to travel through the empty vacuum of space. Sunlight and ultraviolet radiation that both light and heat our planet, travel millions of miles from the Sun to Earth by EM waves.

EM Waves are transverse waves All electromagnetic waves are transverse waves. Transverse waves move up and down or side to side at repeated right angles in the direction of the wave’s energy.

Parts of a transverse wave ? Frequency Prompt students to guess what the teal box, then the blue box, is hiding. (Wavelength, Amplitude) ?

Electromagnetic waves All EM waves travel at the speed of light which is 300 million m/s. The Sun is 150 gigameters or 95 million miles away from the Earth. Traveling at the speed of light, it take sunlight 8 minutes and 20 seconds to reach Earth….WOW!

The Electromagnetic Spectrum https://youtu.be/HPcAWNlVl-8

Radio waves Longest wavelength EM waves Uses: TV broadcasting AM and FM broadcast radio Avalanche beacons Heart rate monitors Cell phone communication Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

Microwaves Wavelengths from 1 mm- 1 m Uses: Microwave ovens Bluetooth headsets Broadband Wireless Internet Radar GPS Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

Infrared Radiation Wavelengths in between microwaves and visible light Uses: Night vision goggles Remote controls Heat-seeking missiles Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

Visible light Only type of EM wave able to be detected by the human eye (ROY G. BIV) Violet is the highest frequency light Red light is the lowest frequency light Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

Ultraviolet Shorter wavelengths than visible light Uses: Black lights Sterilizing medical equipment Water disinfection Security images on money There is one more UV slide…

Ultraviolet (cont.) UVA UVB and UVC Energy Highest of UV waves Lower than UVA Health risks Can cause DNA damage, leading to skin cancer Responsible for sunburn No serious risk for DNA damage. Can cause Vitamin A deficiency. Table will fill in from left to right, top to bottom as you advance through. Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

X-rays Tiny wavelength, high energy waves Uses: Medical imaging Airport security Inspecting industrial welds Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

Gamma Rays Smallest wavelengths, highest energy EM waves Uses Food irradiation Cancer treatment Treating wood flooring Click the little rainbow box in the top right corner to return to the overview EM spectrum diagram

Video Wrap-Up https://www.youtube.com/watch?v=PVPwGsaHups