P13(13.1-13.5) Electromagnetic waves Flashcards
Are electromagnetic waves longitudinal or transverse waves?
-transverse
Explain why electromagnetic waves are not mechanical waves.
-they can travel through a vacuum(don’t need a substance to travel through)
What do electromagnetic waves transfer from their source to an absorber?
-energy
List the different types of waves in the electromagnetic spectrum in order of decreasing wavelength (increasing
frequency).
-Radio
-Microwave
-infrared
-visible light
-ultraviolet light
-x ray
-gamma ray
Which part of the electromagnetic spectrum can humans see?
-visible light
How can electromagnetic waves be produced?
- changes inside an atom/atomic nucleus
How are gamma rays produced?
- changes in the nucleus of an atom e.g during radioactive decay
How can radio waves be produced?
-oscillations in an electrical circuit
How can we detect radio waves?
-Waves are absorbed and create an alternating current
with the same frequency as the radio wave
What are radio waves used for?
-transmitting television, mobile phone, and bluetooth
signals
What are microwaves used for
-satellite communications and cooking food
What is infrared radiation used for?
heating, remote controls, infrared cameras, cooking food
Which types of electromagnetic waves are harmful to the human body?
-ultraviolet, x rays , gamma rays
What are the hazards of being exposed to
ultraviolet radiation?
-damage skin cells, sunburn, increase risk of skin cancer,
age skin prematurely, blindness
Why are X-rays used for medical imaging?
-they pass through flesh but not bone
