Electromagnetic Spectrum

The EM Spectrum What do a radio, heat lamp, the Sun, and an X-ray Machine have in Common? – All four transmit energy through waves. Electromagnetic Waves – Electromagnetic Waves do not need a medium to travel through.

What is the EM Spectrum? Range of radiant energy arranged in order of wavelength and frequency. Each type of wave on the spectrum has a different effect and use. Scientists use the EM spectrum to measure distances as well as figure out what the objects in space are made of. (Spectral Analysis)

Radio Waves Radio waves have some of the longest wavelengths of all EM Waves. Low Energy Waves Used by all radio and television stations. Travel easily through our atmosphere.

Microwaves Microwaves have shorter wavelengths and higher frequencies than radio waves. Carry more energy than radio waves. In a microwave oven, the waves cause water molecules inside the food to vibrate. The food absorbs the energy and gets warmer. Also used in cell phones and radars.

Infrared Waves Shorter wavelengths than microwaves. More energy than microwaves. Used by sensors in satellites and in remotes. Snakes have specialized organs used to detect infrared radiation, which helps locate warm blooded prey.

Visible light Shorter wavelength than infrared waves. More energy than infrared waves. Only part of the EM spectrum we can see. Contains all colors of light. Red has the least energy while violet has the most. Visible light helps understand the chemical composition of stars.

Ultraviolet Light UV rays has a shorter wavelengths and greater energy than visible light. Too much UV light can be bad for your skin. (Sun Burn) However, the right amount can be beneficial because it helps the body produce Vitamin D.

X-Rays Short Wavelengths with high energy waves. Useful for medical reasons but can also be dangerous if overexposed.

Gamma Rays Gamma rays have even more energy than X- Rays. They have the shortest wavelength on the EM Spectrum. Sometimes used to treat cancer. Produced by some nuclear reactions. Thankfully, Earths magnetic field protects us from these dangerous rays.

Summary Scientists use the EM spectrum to measure distances in space. Can also be used to know the make up of a star. Contains 7 different waves – Gamma, X-Ray, UV, Visible light, Infrared, Microwaves, and Radio Waves – All have a different frequency and wavelength.