The Electromagnetic Spectrum
In the electromagnetic spectrum there are 7 main types of radiation – Radio Waves, Microwaves, Infra-red, Visible Light, Ultra-violet, X-rays and Gamma Rays. These waves do not transfer matter – the energy they transfer depends on the wavelength of waves. This is why waves have different effects (like the intensities of Ultra-violet radiation compared to that of Visible Light – although next to each other on the spectrum, UV light can damage your skin and give you skin cancer whilst Visible Light does not cause such effects). The number of electromagnetic waves of a certain wavelength is the number of complete waves passing a point each second. The unit of frequency for Hz is: 1 Herz (Hz) = 1 complete wave per second
1 Kiloherz (Hz) = 1,000 Hz
1 Megaherz (MHz) = 1,000,000Hz
All Electromagnetic waves travel at 300 million m/s through space or in a vacuum. This distance is that which the waves travel each second.
Very High Frequency
Uses in Medical and Industry
Carry a lot of Energy
Can penetrate skin
Produced by firing many Electrons with lots of Energy
Stars Give of X-Rays
Can cause cancer
Used to examine bags in airports
They are used by Astronomers
Dangers: X-Rays can cause cell damage and cancers in excessive use.
Emitted by Stars and Radioactive substances
Can pass through most substances
Used to kill Cancerous Cells
Hospitals take precautions when using Gamma Rays as they can make some cells cancerous when epxosed to them in frequent, lower doses.
Its wavelength is shorter than the violet end of the visible spectrum, and longer than that of an X-ray. UV Light can break chemical bonds, making molecules unusually reactive. Sunburn, for example, is caused by the effects of UV radiation on skin cells, which is the main cause of skin cancer. The Sun emits a large amount of UV radiation
This light could make Earth barren but it is...
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