Noadswood Science, 2012. To understand LDRs and thermistors Thursday, August 13, 2015.
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Transcript of Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the...
![Page 1: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/1.jpg)
Noadswood Science, 2011
![Page 2: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/2.jpg)
To understand the hazards caused by some wavelengths of the electromagnetic spectrum
Friday, April 21, 2023
![Page 3: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/3.jpg)
Complete the electromagnetic spectrum worksheet
![Page 4: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/4.jpg)
![Page 5: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/5.jpg)
Waves transfer energy without transferring mater, and the amount of energy transferred varies with the wave
EM radiation can be absorbed, reflected or transmitted: -◦ Absorbed – the energy of the wave is transferred to the
matter◦ Reflected – the wave bounces back◦ Transmitted – the wave passes through a substance
The different wavelengths of EM radiation interact differently with matter
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Some radiations are more harmful than others – when EM radiation enters living tissue it is often harmless, but some EM radiation can cause serious problems
What effect radiation has depends on its wavelength and the size of the dose
![Page 7: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/7.jpg)
EM radiation such as radio waves pass through soft tissue without being absorbed
EM radiation such as microwaves are absorbed and cause heating of the cells
Some EM radiation causes cancerous changes in living cells (UV radiation can cause skin cancer with some actually destroying cells (radiation sickness after a nuclear accident)
![Page 8: Noadswood Science, 2011. To understand the hazards caused by some wavelengths of the electromagnetic spectrum Monday, May 04, 2015.](https://reader033.fdocuments.net/reader033/viewer/2022051621/56649cba5503460f94982c02/html5/thumbnails/8.jpg)
Higher frequency EM radiation is usually more dangerous – this is because the energy of an EM wave if directly proportional to its frequency
Higher frequency waves such as X-rays and gamma rays have more energy, and it is the energy of the wave which causes the damage
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Some wavelengths of microwaves are absorbed by water molecules, heating them up (this could be a problem as your cells have a large amount of water in them)
Mobile phone networks use microwaves, however there is no conclusive proof if they do / do not cause problems
UV radiation can damage DNA in cells (fluorescent tubes emit UV radiation, requiring special coatings to absorb this unwanted UV radiation)
X-rays can cause mutations, leading to cancers
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Radiation can cause ionisation – the energy of the wave can bash into atoms, knocking electrons off them resulting in ions (charged)
The further radiation can penetrate before hitting an atom and getting stopped, the less damage it will do along the way (less ionising it is)
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Research the dangers of different wavelengths, and the precautions that must be taken
Pick one of the following areas: -◦ Sun beds and too much Sun (UV radiation)◦ Mobile phone networks (Microwaves)◦ X-rays◦ Gamma radiation from nuclear radiation, e.g. Chernobyl
disaster
Identify what dangers the radiation can cause, do the dangers have scientific basis, and what precautions should be taken to avoid harm – make a poster / movie / PowerPoint