Flashcards
EM spectrum
Flashcards do conjunto (5)
- 1—~all EM waves are transverse
~They all travel the same speed in a vacuum, eg.space
~ The higher the frequency the shorter the wavelength
~the higher the frequency the more penetrative the wave is - 2Radio waves ~used to broadcast TV and radio signals ~Long-wave radio can be transmitted around the world. ~ Radio waves carry few or no dangers because of their low frequency and long wavelength.Microwaves
~used for satellite communication and mobile phones
~Microwaves can cause heating
~Microwaves can heat human body cells, and are therefore a danger. - 3Infrared radiation ~ used as a heat detecting radiation ~ The higher the temperature the brighter the image appears, used by police ~ Can also heat sells by causing them to vibrate, IR has higher frequency so can cause skin burnsVisible light
~Visible light is required to see objects
~Visible light is reflected off objects
~ visible light is used in photography in a similar way to the eye
~ Can cause blindness in extreme cases. - 4Ultraviolet ~ UV is absorbed by fluorescent ~ UV is used to detect forged bank notes with no fluorescent markings ~ Can also be used to disinfect water ~ high frequency means ionising so can mutate cells cause cancer and eye damageX-Rays
~ X-rays in hospitals not absorbed by denser materials so shows bone structure
~Also used in airports to scan baggage
~ More ionising, can cause cell mutation and cancer. more penetrative - 5Gamma rays ~ Ionising radiation, can cause cancer and mutations ~ can also be used to sterilise food ~ Can treat cancer by killing cancerous cells ~ Highest frequency EM waveIonising radiation
~ alpha beta and gamma radiations are all ionising
~ emitted when radioactive nuclei decays
~ They 'knock off' electrons which makes them ionising
~ They can all cause cancer and mutations
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- Descrição
- FlashCards sobre EM spectrum, criado por jrelf19 em 26-01-2015.
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- jrelf19
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