Ultra violet (electromagnetic spectrum)

ultra violet light , part of the electromagnetic spectrum , light wave , many uses, transverse wave,

1. Ultra Violet

2. What are UV rays? Ultraviolet (UV) rays are invisible rays that are part of the energy that comes from the sun. UV rays  can burn the eyes, hair, and skin if these parts of the body are not properly protected, or if they under go too much exposure to the sun. Nevertheless, UV rays are very useful in our ecosystem.

3. Ultraviolet  ( UV is a wavelength shorter than that of visible light, but longer than X-rays, that is, in the range 10  nm to 400 nm, c. it is named like this because it lays above the violet color in the seven colors of the spectrum.

4. UV light is found in sunlight (where it constitutes about 10% of the energy in vacuum) and is emitted by electric arcs and specialized lights such as mercury lamps and black lights. It can cause chemical reactions, and causes many substances to glow or  fluoresce.

5. UV  rays assist our bodies in making vitamin D, which strengthens bones and teeth and helps our bodies build immunities to such diseases as Rickets and colon cancer. UV rays are also used to treat psoriasis; the rays slow the growth of skin cells, preventing the outbreak of the itchy patches for which psoriasis is known. UV rays have various commercial uses as well, including sterilization and disinfection. Some animals can see UV rays, and UV vision helps bees to collect pollen from flowers .

6. In spite of all their positive uses, UV rays remain very harmful for anyone who spends a large amount of time in the sun without proper protection. The most common effect of exposure to UV rays is sunburn. Sunburn is the damage caused to skin cells when they have absorbed too much energy from UV rays. Sunburn causes blood to rush to the affected area as the body tries to cool the burn, and the damaged skin ultimately peels away. In addition to the burning pain on the skin, sunburn can ultimately cause  skin cancer .

7. Skin cancer is often caused by prolonged exposure to UV rays

8. The best way to combat UV rays is with bodily protection. Always wear protective sunglasses and a hat to protect the eyes. A hat will also protect hair from UV damage, as well as the skin on the face and neck

9. While the best protection for the skin is long, loose clothing, this is not always practical, so the next best option is a protective  sunscreen . There are many types of sunscreen, but they all have a number indicating how protective they are against harmful UV rays. The higher the number, the more protection they provide. Always use sunscreen, even if you will only be in the sun for a few minutes. Be smart, cover up, use sunscreen and enjoy the sunshine!

10. http://www.youtube.com/watch?v=np-BBJyl-go

11. Thank you