1. 25.1 The Electromagnetic Spectrum

2. Light is a kind of wave A sound wave is a oscillation of air.
A water wave is an oscillation of the surface of water.
An oscillation of electricity or magnetism creates electromagnetic waves.

3. 25.1 Electromagnetic waves
If you could shake the magnet up and down 100 million times per second, you would make FM radio waves at 100 million Hz (100 MHz).

4. 25.1 Electromagnetic waves
In a similar way, the force between two electric charges is carried by an electric field.

5. The Electromagnetic Spectrum
Light is a form of electromagnetic energy.
Longer wavelength = lower frequency = lower energy
Shorter wavelength = Higher frequency = higher energy

6. Electromagnetic Spectrum EXAMPLE
List the following types of electromagnetic waves in order of increasing energy:
Visible light
X-rays
Microwaves
Gamma rays

7. Visible Light
Different colored light has different energies.

8. Speed of Light
speed of light = 3 x 108 m/s

9. Speed of Light EXAMPLE speed of light = 3 x 108 m/s
What is the frequency of a wave with a wavelength of 340 nm (340 x 10-9 m)?