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Ultraviolet Rays

Ultraviolet Rays. What are ultraviolet rays?. A type of electromagnetic wave with a shorter wave length. They are invisible to the naked eye, and typically come from the suns radiation to the earth.

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Ultraviolet Rays

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  1. Ultraviolet Rays

  2. What are ultraviolet rays? • A type of electromagnetic wave with a shorter wave length. They are invisible to the naked eye, and typically come from the suns radiation to the earth. • Ultraviolet means beyond violet, and violet is the color of the shortest wavelength of visible light.

  3. The Discoverer • Johann Wilhelm Ritter • Dec 16 1776- Jan 23 1810 • German chemist and physicist • Died at a young age, they believe it was because he used his own body in his electrical experiments.

  4. How did he discover it? • After hearing of Hershel's discovery of Infrared light, and it being non visible, he decided to conduct experiments as well. • Ritter realized that silver salts/silver chloride darkened when it was exposed to sunlight • He called them de-oxidizing rays (taking the effects of oxygen away)

  5. Frequency and Wavelength • 750-30,000 THz = frequency range • 400-10 nm = wavelength

  6. How is it used? • In medicine it kills bacteria and viruses • Disinfecting water, food processing • Sun tanning • security (credit cards, passports, drivers license) • Black lights • Fire Detectors • Sterilization • Lasers • Determining substance abuse in public places A bird shows up on many Visa cards when placed under UV lights

  7. Does it have any effects? • Therapeutic purposes (such as treating skin disease) • It is the biggest cause for skin cancer. • Ages skin faster • Trigger allergic reactions • Long exposures can result in blindness over time • Sunburns Malignant melanoma-one of the three skin cancers you can get.

  8. Interesting… • Ultraviolet tattoo • Suntans come from after they have killed your skin cells, and damaged others. • On average around 70 - 80% of a person’s life time exposure to the sun occurs by the age of 18. • Approximately 80 - 85% of UV rays pass through clouds. • Cat urine, and scorpions both glow in black light Does this work? You can buy it on ebay…

  9. sources • http://en.wikipedia.org/wiki/Ultraviolet_Rays • www.spacebuffs.com/glossary • Google images: UV rays • information from the BG health department www.hvbg.de/e/bia/fac/strahl/uv_str_e.pdf • http://simun.inspiringteachers.com/custom2.html

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