Electromagnetic Spectrum 

Short waves (1) ...... Long waves (7)

[short waves] 100 nm  -  280 nm  -  320 nm  -  400 nm [long waves]  
(nm = nanometers)

1. Gamma Rays
2. X-rays
3. Ultraviolet
   • UV-C  (Ultraviolet-C)
     100-280 nm
     __________
     Dangerous Rays
   • UV-B (Ultraviolet-B)
     280-315 nm
     __________
     Burning Rays
   • UV-A (Ultraviolet-A)
     315-400 nm
     __________
     Tanning Rays
4. Visible
5. Infrared
6. Microwave
7. Radio