Chapter 11
Electromagnetic spectrum
Radio waves
Microwaves
Infra-red waves
Visible light waves
Ultra-violet waves
X-rays
Gamma rays
Lowest frequency
Highest frequency
EM waves
All EM waves are transverse
All oscillate electric and magnetic fields
All travel at 3.0 x 10^8 m/s in a vacuum
The EM wave's speed can be different when switching from one medium to another, but the frequency of the wave remains the same
They transfer energy
ionizing waves have higher frequencies which leads them to eject electrons from atoms and molecules, making them become ions. This can cause harm to the cell as the ions can disrupt cell functions or even kill them.
Used for communication
Used for radio and television broadcasting
Used for communication through satellite communication and mobile phones
Used in the Global positioning system(GPS)
Used for cooking
Used for remote controls
Used for photography
Used for medicine(Optical glass fibre
Used for sterilization and disinfection
Used for Anti-Forgery notes
Security scanning(Check contents of a luggage)
Quality control(Check for defects in a product)
Disinfection and sterilisation
Radiotherapy
Over-exposure leads to sun burn on the skin, leading to skin cancer
ionizing waves have higher frequencies which leads them to eject electrons from atoms and molecules, making them become ions. This can cause harm to the cell as the ions can disrupt cell functions or even kill them.