The Electromagnetic Spectrum

GCSE Core Science (Physics) AQA revision

What is the electromagnetic spectrum?

The electromagnetic Spectrum is all the possibilities of electromagnetic radiation. Electromagnetic waves are vibrations of magnetic and electric fields. The longer the wavelength, the lower the frequency and the shorter the wavelength, the higher the frequency.

What do you need to know for GCSE?

. The names of the types of waves


.The order that they are arranged in


. How each type of wave is made


.The dangers of each type of wave


.All electromagnetic waves can travel through a vacuum.


.All electromagnetic waves can travel at the speed of light

Gamma rays

. Gamma rays are emitted from stars and other radioactive substances


. Gamma rays are extremely high frequency rays and they carry a lot of energy


. They pass though most materials and they are so difficult to stop that you need lead or concrete to block them out


.Gamma rays are used in radiotherapy to kill cancer cells and this works because cancer cells can't repair themselves like ordinary body cells. This is why it is important to get the dosage right. Targeted radiotherapy is a radioactive substance used to kill cancer cells, but it is taken up by specific part of the body, so the rest of the body gets a low dose. In addition, an example of this be using radioactive iodine to treat cancer in the thyroid gland.