1. Components
1.1. Radio waves
1.1.1. Found in Radio Transmission Devices.
1.1.1.1. Used for radio broadcasting, TV broadcasting, remote control cars and walkie-talkies.
1.2. Microwaves
1.2.1. Found in special electronic devices such as klystron.
1.2.1.1. Used in Microwaves to cook food uniformly.
1.3. Infrared (IR)
1.3.1. Emitted from the Sun.
1.3.1.1. Used for night vision equipment, remote control, TV or radio.
1.4. Visible light
1.4.1. Emitted from the sun and heated bodies.
1.4.1.1. Used in Optical fibres, light photography and endoscopy
1.5. Ultra-violet rays (UV)
1.5.1. Obtained from sunlight
1.5.1.1. Used to check counterfeit notes
1.6. X-rays
1.6.1. Produced by firing high speed electrons at metal target.
1.6.1.1. Used for medical imaging, scanners at airports.
1.7. Gamma rays
1.7.1. Emitted from hazardous nuclear radiation
1.7.1.1. Used to kill harmful bacteria and viruses.
2. Electromagnetic waves are non-mechanical and transverse waves. They consist of electric and magnetc fields oscillate perpendicularly to each other.
3. Properties
3.1. Transverse waves
3.2. Does not require medium to propagate
3.3. Travel at a constant speed of 3.0 x 10^8 ms-1
3.4. Obey laws of reflection and refraction
4. Harmful Effects of Radiation
4.1. Ionizing radiation from UV rays, X-rays and Gamma rays.
4.1.1. Cause electrons to gain energy and escape from the atoms and become unstable. Unstable atoms likely to initiate reactions and cause mutation in cells due to damaged DNA.