Chapter 3 The Electromagnetic Spectrum

Electromagnetic waves transverse waves that have some electrical properties and some magnetic properties. - consists of changing electric and magnetic fields Electric fields: a region in which charged particles can be pushed or pulled. Magnetic fields: a region in which magnetic forces are present.

Electromagnetic waves in motion

Electromagnetic Radiation the energy that is transferred by electromagnetic waves does not need a medium.

Light: properties of both waves and a stream of particles. Polarized Light: light that passes through a filter

Polarized Light

Photoelectric effect the movement of electrons in a substance when light is shined on it.

Photoelectic energy The photoelectric effect has practical applications in photoelectrical cells used for solar powered cars, and solar powered calculators.

Characteristics of EMS Waves: all E.W. travel at the same speed Each type of wave has a different wavelength Each type of wave has different frequencies

Electromagnetic Spectrum: the complete range of E.W. placed in order of increasing frequency

Clicking the little rainbow box at the top of each slide will bring you back to this one

Longest Wavelength Shortest Wavelength Lowest frequency ____Highest frequency Lowest Energy ____Highest Energy Radio Microwave Infrared Visible UV Rays X-rays Gamma rays light

Radio Waves E.W. with the longest wavelength and lowest frequencies Uses: radar: a system that uses reflected radio waves to detect objects and measure their distance and speed. TV broadcasting AM and FM broadcast radio Heart rate monitors Cell phone communication

Microwaves Radio waves with a shorter wavelength Uses: Microwave ovens Bluetooth headsets Broadband Wireless Internet Radar GPS

Infrared Rays E.W. with wavelengths shorter than radio waves Uses: Night vision goggles Heat lamps Infrared cameras Remote controls Heat-seeking missiles

Visible Light E.W. that you can see. - longest wavelength, red - shortest wavelength, violet - white light = mixture of colors (can be seen with the use of a prism)

Ultraviolet Rays carry more energy b/c they have higher frequencies than visible light and shorter wavelength. Uses: Black lights Sterilizing medical equipment Water disinfection Security images on money

X-Rays E.W. with more energy than UV rays. can penetrate most matter, except bones (denser matter) Uses: Medical imaging Airport security Inspecting industrial welds

Gamma Rays E.W. with the most amount of energy and highest frequency and the shortest wavelengths. Uses Food irradiation Cancer diagnosis and treatment