1. Harmful effects
1.1. Ionization radiation
1.1.1. UV rays
1.1.1.1. Excessive exposure to UV rays can result in skin pigmentation & cancer
1.1.2. X rays
1.1.2.1. Gamma rays and X-rays have high penetrating and ionising power. Radiation sickness, cell mutation and cancer may occur
1.1.3. Gamma rays
1.1.4. Definition: Cause electrons to gain energy and escape from atoms
1.1.5. Cause atoms to become charged and unstable, initiate reactions, cause mutation in cells due to damaged DNA
2. Facts
2.1. Travels at constant speed of 3.0 x 10^8 ms-1
2.2. Travel with same high speed in vacuo
2.3. Higher the frequency, lower the wavelength (vice-versa)
3. Source
3.1. Radio waves
3.1.1. Produced by electrical circuits
3.2. Microwaves
3.2.1. Special electronic devices E.g. Klystron
3.3. Infared
3.3.1. Hot objects
3.4. Light
3.4.1. Sunlight
3.5. UV rays
3.5.1. Sunlight
3.6. X rays
3.6.1. Firing high speed electrons at a metal
3.7. Gamma rays
3.7.1. Radioactive decay of unstable atoms and during nuclear reactions
4. Uses
4.1. Radio waves
4.1.1. Radio communication
4.1.1.1. Longer wavelength
4.1.1.1.1. AM radio
4.1.1.2. Shorter wavelength
4.1.1.2.1. FM radio
4.1.1.2.2. TV
4.1.2. Television communication
4.1.3. Radar
4.2. Microwaves
4.2.1. Satellite television
4.2.2. Telephone
4.2.3. Microwave oven
4.3. Infared
4.3.1. Household electrical appliances
4.3.2. Remote controllers
4.3.2.1. E.g. TV
4.3.3. Intruder alarms
4.4. Light
4.4.1. Optical fibres
4.4.2. Medical uses
4.4.3. Telecommunications
4.4.4. Light Photography
4.4.5. Ends of spectrum are Red and Violet, many uses
4.5. UV rays
4.5.1. Sunbeds
4.5.2. Fluorescent tubes
4.5.3. Sterilisation
4.5.4. Different types
4.5.4.1. E.g. UVA
4.5.4.2. E.g. UVB
4.6. X rays
4.6.1. Hospital use
4.6.2. Engineering applications
4.6.3. Scanners
4.6.3.1. E.g. Medical imaging
4.7. Gamma rays
4.7.1. Medical treatment
4.7.1.1. E.g. Cancer treatment