Electromagnetic spectrum
by goh ben-yi
1. Radio waves
1.1. 1) Has the longest wavelengths in the electromagnetic spectrum. 2) Ranges from several hundred metres to a few centimetres. 3) Used in radio and television communication to transmit sound and pictures.
2. Microwaves
2.1. 1) Microwaves are radio waves of very short wavelengths. 2) Have wavelengths of a few centimetres. 3) Used for satellite communications,Satellite television and mobile phone networks.
3. X-Rays
3.1. 1) Produced when high energy electrons lose energy after striking a metal target. 2) Used as a diagnostic tool in medicine and dentistry. 3)
4. Gamma Rays
4.1. 1) Emitted by radioactive nuclei and are released during nuclear reactions. 2) They penetrate very deeply and cause serious. 3) Used to treat cancer and checking welds.
5. Infra-red Radiation
5.1. 1) These are waves just beyond the red end of the spectrum. 2) When objects absorb infra-red radiation, the become hotter. 3) The property of it is used to provide heat treatment for various illnesses.
6. Visible light
6.1. 1) The most familiar form of the electromagnetic spectrum that the human eye can detect. 2) Ranges from colours such as Violet to Red. 3) Used to weld metals together and cut through hard materials like steel.
7. Ultra-Violet Radiation
7.1. 1) It is the radiation beyond the violet end of the visible spectrum. 2) Main source is sunlight. 3) Kills bacteria and viruses, thus it is used to sterilise hospital operating rooms and surgical instruments.
