2 Electromagnetic waves are transverse waves consisting of changing electric and magnetic fields. Energy travels in the form of waves.They can travel in a vacuum as well as through matter.Electromagnetic radiation-the transfer of energy byelectromagnetic wavestraveling through matter oracross space.
3 Light, like sound and heat, is a form of energy. The visible light we see is part of the electromagnetic spectrum.
4 Things to know…frequency– how often a wave passes a point in a certain time intervalwavelength- the distance from one crest to the next or one trough to the next
6 The speed of light in a vacuum is: 3 X 108 meters per second (300,000,000 m/sec)
7 The Electromagnetic Spectrum Electromagnetic Spectrum- the full range of frequencies of electromagnetic radiation.This spectrum includes visible light and invisible waves:radio wavemicrowavesinfrared lightultraviolet lightX-raysgamma rays
15 Radio Waves Has the longest wavelength and the lowest frequency. Uses: Radio, TV, radar, microwavesRadar: radio detection and ranging, a system that uses reflected radio waves to determine the velocity and location of objects
16 Microwaves Microwaves are used in cooking and communication. Microwaves have wavelengths in the range of centimeters.
17 Infrared Rays Wavelength smaller than radio. slightly longer than red visible light.felt as warmthUsed as a source of heat/or to detect heat differences.Thermograms-color-coded picturesthat show variationsin temperature.
18 Visible LightEach wavelength in the visible spectrum corresponds with a specific frequency and a specific color.Light enables peopleto see, keeps peoplesafe and helps themto communicate.
19 Ultraviolet RaysShorter wavelength and higher frequency than violet light.Sunlight contains ultraviolet light.The invisible light that lies just beyond violet light falls into the ultraviolet (UV) portion of the spectrum.
20 X-Rays Have very short wavelengths. Less than 10–8 m.Used in medicine, industry and transportation by making pictures of the inside of solid objects.
21 Gamma Rays Shortest wavelength in the electromagnetic spectrum. wavelengths shorter than 10–10 m.Have the highest frequency.Have the most energy.Over exposure can bedeadly.Used in the medical fieldto kill cancer cells and make pictures of the brain, and in industrial situations as an inspection tool.