Electromagnetic Spectrum notes P1 Physics GCSE

These are notes on the wave spectrum :) hope they help with your revising!

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Order

This is the order of the electromagnetic spectrum:

Radio Waves > Microwaves > Infra-red > Visible light > Ultraviolet > X-ray > Gamma rays.

These waves go in order from long wavelength and a lower frequency >>>>  

So radio waves have a longer wavelength than microwaves but microwaves have a longer wavelength than infra-red and so on... until we get to gamma rays which have the shortest wavelength.

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Radio Waves

Sources:
Brings music to radios, carrys signals for TV and cellular phones.

Uses:
Mainly used for communications, conveys information from one place to another without the use of wires. Transmits sound and TV signals.

Dangers to health:
Radio waves can break down tissue in the body and wreak havoc with DNA. Some say that these waves could cause brain tumours, headaches, sleep disprders, cancer...

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Microwaves

Uses:
Used to heat food in a microwave oven. They can also be used for communications as they can pass through the atmosphere and reach satelites orbiting the Earth.

Dangers to health:
They can penetrate living tissues and heat water inside living cells which can damage or even kill cells. 

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Infra-red radiation

Sources:
Warm/hot objects e.g the sun, irons, fires, grills, toasters (basically any object that has a temperature of above absolute zero emits infra-red radiation. 

Uses:
Infra-red scanners are used in medicine to detect hot spots on the body. They are also used for night- vision cameras.

Dangers to health:
Can be absorbed by skin and can damage or even kill cells by heating them.

Interesting point:
The hotter an object is the more infra-red radiation it will emit. 

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Visible light

Sources:
Any illuminous source e.g hot objects, the sun, flourescent substances, lasers, LED's...

Uses:
To light up rooms or other dark places, so that you can see where you are going in the day.

Dangers to health:
If you stare at an object for a long time it can damage your sight and you can eventually go blind.

Interesting points:
It only takes 8minutes for light to travel from the sun to Earth. You can see the colours of visible light through a prism (the colours are red, orange, yellow, geen, blue, indigo and violet). Our eyes are most sensitive to yellow and green light. 

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Ultraviolet light

Sources:
Hot objects e.g the sun, sparks, mercury lamps. 

Uses:
Uses for UV light include getting a sun tan ( provides the body with vitamin D), detecting forged bank notes in shops, and hardening some types of dental filling. You also see UV lamps in clubs, where they make your clothes glow. This happens because substances in washing powder "fluoresce" when UV light strikes them. When you mark your posessions with a security marker pen, the ink is invisible unless you shine a UV lamp at it. Ultraviolet rays can be used to kill microbes. Hospitals use UV lamps to sterilise surgical equipment and the air in operating theatres. Food and drug companies also use UV lamps to sterilise their products. 

Dangers to health
Can cause blindness and can cause sunburn which leads to cancer if exposed to too much UV light. 


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X-rays

Sources:
X-ray tubes.

Uses:
To x-ray people, to inspect teeth and bones, can also kill cancer cells.

Dangers to health:
Can cause cells to become cancerous. 

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Gamma rays

Sources:
Cobalt

Uses:
Can be used to steralise surgical instruments and food so that it doesn't go off as quick. Kills bacteria, can also kill cancer cells. They can detect leaks in pipes underground.

Dangers to health:
Mutates DNA causing lumps. Can damage intestines and fertility. Can also make your body radioactive.

Interesting points:
Gamma rays aren't affected by the magnectic field.  

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You should try and remember as many uses and dangers of the waves of the electromagnetic spectrum because questions involving this could come up in your tests.

Hope my revision notes have helped you!!

Please comment below :) thanks :)

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Comments

Kayleigh

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thank you **

Ashley

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Thank You :)

JJay

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Thank you

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