The Electromagnetic Spectrum Flashcards
At what speed can all electromagnetic waves travel at through a vacuum?
300,000,000m/s
What happens to the wavelength, frequency and energy as we go from radio waves to gamma radiation?
Wavelength gets shorter
Frequency gets higher
Energy gets higher
Give the use and hazard of radio waves
Use: radio and tv communication
Hazard: probably none at these low energy levels
Give a use and hazard of microwaves
Use: cooking and mobile phones
Hazard: heating of water within tissue.
Give a use and hazard for infrared radiation
Use: TV remote controls and security cameras
Hazard: causes burning of tissue
Give a use and hazard of visible light
Use: being able to see
Hazard: damage to retina at high light levels
Give a use and hazard of ultra violet radiation
Use: security markings and tanning bulbs
Hazard: high doses can cause skin cancer
Give a use and hazard of X-rays
Use: medicine and airport security scanners
Hazard: radiation hazard - penetrates matter and causes damage to cells.
Give a use and hazard for gamma radiation
Use: kills bacteria and destroys cancerous cells
Hazard: radiation hazard - penetrates matter and causes damage to cells and DNA
Explain how a microwave works
Microwave energy is absorbed by water molecules contained within objects, heating them up. The water molecules then transfer the heat to surrounding molecules whether they are in food or in our bodies.
Which two waves in the spectrum are most harmful to humans?
Gamma rays and ultra violet waves
State two characteristics of all electromagnetic waves.
All travel through a vacuum of 300,000,000 m/s
All electromagnetic waves are transverse waves
Name a wave which can be longitudinal or transverse
Mechanical waves
What are electromagnetic waves?
Electromagnetic waves are disturbances in the electric and magnetic fields, which can exist in a vacuum. They are transverse and carry energy from one place to another.
