Electromagnetic Spectrum and Colors

The EM Spectrum

Speed of all electromagnetic waves is constant = speed of light High Frequency = Small Wavelength = High Energy Gamma Rays Low Frequency = Large Wavelength = Low Energy Radio Waves

Energy

Radio Waves Wavelengths Sources Uses 30 cm to longer than our planet Stars Transmitters Uses AM Radio = Amplitude Modulation FM Radio = Frequency Modulation Television Cell phones Radar

Energy

Microwaves Wavelengths Sources Uses 30 cm to 1 mm Stars Magnetron In microwave ovens Cell phones, GPS Wi-Fi Doppler Radar (Weather maps) Radar

Energy

Infrared Waves Wavelengths Sources Uses 1 mm to 700 nm Stars Organisms Heat Sources Uses Night Vision Thermal Imaging Remote Controls

Energy

Visible Light Region of the EM spectrum that the human eye can detect All the colors (ROYGBIV - this is order of colors in increasing energy / decreasing wavelength / increasing frequency) Wavelengths 700 nm to 400 nm Sources Stars Light Bulbs Lasers Uses Sight Communication R O Y G. B I V red orange yellow green blue indigo violet

Energy

Ultraviolet Waves Wavelengths Sources Uses UVA = tanning, wrinkles 400 nm to 60 nm Sources Stars Black Lights (UVA) Mercury-Vapor Lamps (UVB and UVC) Uses Sterilization Security Forensics Chemical Markers UVA = tanning, wrinkles UVB = tanning, sunburn, cancer UVC = used for sterilization, most dangerous

Energy

X-Rays Wavelengths Sources Uses 60 nm to 0.0001 nm Sources Stars X-Ray Tubes Uses Medical Imaging Security Astronomy Can penetrate soft tissue, but not bone

Energy

Radiation treatment using radioactive cobalt-60. Gamma Rays Wavelengths 0.1 nm to 0.00001 nm Sources Radioactive atoms (radioactive waste from nuclear fission plants releases gamma rays) Stars Uses Cancer radiation treatments Radiation treatment using radioactive cobalt-60.

Light and Color Opaque Translucent Transparent Absorbs or reflects all light (can’t see through it) Translucent Allows some light to pass through it Transparent Allows light to pass through completely

Additive Color White light In white light, an object… contains all visible colors - ROYGBIV In white light, an object… reflects the color you see absorbs all other colors Primary Additive Colors Red Green Blue Examples Computer Monitors (kinda) Televisions (kinda)

Subtractive Color Pigments, Dyes, Inks, Paints colored material that absorbs and reflects different colors Primary Subtractive Colors Magenta Cyan Yellow Examples Color Ink Cartridges

Negative Afterimage - One set of cones gets tired, and the remaining cones produce an image in the complimentary color.

Vocabulary: Order of all 7 EM waves (longest to shortest wavelength) Order of all 7 colors (longest to shortest wavelength) Uses of Radio Waves Uses of Microwaves Uses of Infrared Uses of Visible Light Uses of Ultraviolet Uses of X-Rays Uses of Gamma Rays Opaque Translucent Transparent 3 Primary Additive Colors of Light 3 Subtractive Colors of Light

Exit Ticket: #9-12

9. What type of electromagnetic radiation has the longest wavelength? Gamma rays Microwaves Light waves Radio waves

10. What type of electromagnetic radiation has the highest frequency? Gamma rays Microwaves Ultraviolet waves Radio waves

11. What type of electromagnetic radiation has the most energy? Radio waves X-rays Infrared waves Gamma Rays

12. What color has the SHORTEST wavelength? Violet Yellow Red Green