1. Electromagnetic Waves A wave transmits energy from the source to the receiver. Electromagnetic waves do this by disturbing the electric and magnetic fields surrounding the earth. The types of electromagnetic waves are arranged on a spectrum from greatest to smallest frequency.

2. Electromagnetic Spectrum

3. Wave Properties Wavelength (λ) is the distance between two successive waves. Frequency (f) is the number of waves passing a point per second.

4. Electromagnetic Spectrum

5. Color is Frequency

6. Media Frequencies AM radio - 535 kilohertz to 1.7 megahertz Short wave radio - bands from 5.9 megahertz to 26.1 megahertz Citizens band (CB) radio - 26.96 megahertz to 27.41 megahertz Television stations - 54 to 88 megahertz for channels 2 through 6 FM radio - 88 megahertz to 108 megahertz Television stations - 174 to 220 megahertz for channels 7 through 13

7. Household Gadgets Frequencies Garage door openers, alarm systems, etc. - Around 40 megahertz Standard cordless phones: Bands from 40 to 50 megahertz Baby monitors: 49 megahertz Radio controlled airplanes: Around 72 megahertz, which is different from... Radio controlled cars: Around 75 megahertz Wildlife tracking collars: 215 to 220 megahertz Cell Phones: 824 to 849 megahertz New cordless phones: around 900 megahertz!

8. Wave Properties

9. v = f * λ wave speed equation Wave speed (v) is the speed of electromagnetic waves. In a vacuum this is 3.0 x 10 8 m/s or 186,000 miles per second! This is referred to as the “speed of light” though all radiation travels at this speed.

10. Energy of E/M Waves The energy of E/M radiation is proportional to frequency. The more energetic waves are higher in frequency like x-rays. E = h* f h is a constant in nature h = 6.626 x 10 -34 J/Hz

11. Atomic Spectra White light emits all colors because a multitude of electron transitions occur between energy levels. Spectral Lines give evidence of electron transitions. A specific species of gas emits only a limited amount of spectral colors because of a more limited availability of electron transitions.