1. Chapter 18 Electromagnetic Spectrum & Light

2. Electromagnetic Waves Electromagnetic Wave: is a transverse wave consisting of changing electric and magnetic fields. Draw picture: Page 533 Carries energy from one place to another. Does not require a medium to travel Differ from mechanical waves by how they are produced and travel

3. Electromagnetic wave

4. Electromagnetic waves are created by constantly changing electric or magnetic fields Push/Pull effect that moves the waves Electromagnetic waves can travel through a vacuum, empty space, or matter (medium) All travel at the same speed through a vacuum Speed is 3.0 X10 8 m/s (speed of light)

5. Wavelength & Frequency Electromagnetic waves vary in wavelength and frequency (THIS IS HOW E.M. WAVES ARE IDENTIFIED) Indirect relationship – as the wavelength increases, the frequency decreases If you know the wavelength, you can calculate its frequency Speed Frequency = Wavelength

6. Electromagnetic radiation behaves like a wave and a stream of particles Photons are packets/particles of electromagnetic energy Intensity is the rate at which a wave’s energy flows through a given area Light intensity decreases as distance from the light source increases

7. 18.2 Electromagnetic Spectrum Electromagnetic Spectrum is the full range of frequencies of electromagnetic radiation Each wave in the spectrum is characterized by a range of wavelengths and frequencies. Waves, ranging from radio, infrared rays, visible light, ultraviolet rays, x-rays, and gamma rays

8. Left Side of the spectrum Long Wavelength Low frequency Low energy Right Side of the spectrum Short Wavelength High frequency High Energy

9. http://imagine.gsfc.nasa.gov/science/toolbox/ emspectrum1.html http://imagine.gsfc.nasa.gov/science/toolbox/ emspectrum1.html

10. Light spectrum and energy https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0 ahUKEwiVwe2A7uDKAhXD6SYKHQG6CAIQjRwIBw&url=http%3A%2F%2Fww w.drcruzan.com%2FChemistry_Atoms.html&psig=AFQjCNHDwezo1aa8525s0Bz xdsoVRtQZ-A&ust=1454769788227834

11. Radio Waves: are used for the following: Television signals Radio stations Radar- give location of other objects (military) Speed guns that cops use Microwaves- cooking Have longest wavelengths and lowest frequencies

12. Infrared Rays: are used for the following: Heat sources: heat lamps used to keep food warm Thermo-grams: are pictures that show differences in temperature Military use these Hunters

13. Thermograms

14. Visible Light: is located in the middle of the electromagnetic spectrum (light) Visible light ranges from red to purple Copy chart on page 543

15. Ultraviolet Rays: are used in the following areas: Health Kill bacteria and micro organisms (hospitals) UV rays used as a disinfectant Sun: sunburns and skin cancer (sunscreen for protection)

16. X-RAYS: have the second highest frequency, their radiation can hurt or kill living organisms (overexposure) Broken bones Look in suitcases at airport Department of Transportation (Look inside of trucks)

17. Gamma Rays: the highest frequency and energy levels on the spectrum Radiation from the sun Atomic blasts Health benefits MRI pictures Radiation treatment to kill cancer Overexposure can cause death

18. Incandescent Light: is produced when a filament gets hot from the friction of electricity passing through it Incandescent light gives off heat Filament is made from tungsten Fluorescent Light: produces light by exciting a phosphor and causing them to emit photons Does not emit much heat energy Requires less electricity than incandescent Does not give as much heat as incandescent

19. Neon Light: is produced when electricity passes through a noble gas Helium, Neon, Krypton, Argon Advertising Store signs USE LARGE AMOUNTS OF ELECTRICITY EXPENSIVE

20. Red shift blue shift /Doppler effect

21. http://www.lcse.umn.edu/specs/labs/images/doppler.gif

22. Red shift blue shift in space Redshift and blueshift describe how light changes as objects in space (such as stars or galaxies) move closer or farther away from us. The concept is key to charting the universe's expansion. – video See more at: http://www.space.com/25732- redshift-blueshift.html#sthash.GoeViqqw.dpuf

23. When an object moves away from us, the light is shifted to the red end of the spectrum, as its wavelengths get longer. If an object moves closer, the light moves to the blue end of the spectrum, as its wavelengths get shorter. - See more at: http://www.space.com/25732-redshift-blueshift.html#sthash.GoeViqqw.dpuf

24. https://alienspacesciencenews.files.wordpress.com/2013/04/blue-doppler-shifted-light-blue-shift-red-shift-spectra-visible-light-wow-data-line-22-signal-communication.jpg