3.3 Electromagnetic Soectrum Flashcards
State the 7 electromagnetic waves found in the electromagnetic spectrum in order of increasing wavelength.
Gamma, X Ray, UV, Visible, Infrared, Microwaves, Radio
What is the highest frequency electromagnetic wave?
Gamma waves
What is the highest energy electromagnetic wave?
Gamma waves
What is the speed of EM waves in a vacuum? ()
3x10^8 m/s
A wave transmits energy from…
..source to absorber.
e.g. from a light source to the eye
What range of frequencies of electromagnetic waves can be detected by the human eye?
400-700 nanometres
What properties are shared by all electromagnetic waves?
• They are all transverse waves
• They all travel at the same speed (108 m/s)
• They can travel through a vacuum
State and explain a use of radio waves.
Communications, because radio waves are long wavelength and can travel long distances without losing quality.
State and explain a use of microwaves.
Cooking, as microwaves are absorbed and heat fat/water in foods.
State uses of infrared radiation.
Cooking food (as it transfers thermal energy), infrared cameras and short range communication.
State and explain uses of visible light radiation.
Illuminating (i.e. seeing) and fibre optics, as they reflect best in glass (other waves have wavelengths that are too long/short).
State and explain uses of UV radiation.
“-find evidence in crime scenes which is invisible to human eye
-UV light to sterilise water (UV radiation destroys DNA + any bacteria and viruses in water)
“
State and explain uses of X rays.
“-used in security scans at airport
-used in hospitals to see inside patients w/out surgery”
State and explain uses of gamma rays.
“-kill cancerous cells
-sterilising surgical instruments by killing bacteria”
How does UV radiation affect body tissue?
• UV radiation can cause cancer when skin is exposed to it.
• It can cause blindness if eyes are overexposed to UV radiation.
