1. Waves and Electromagnetic Radiation

2. Parts of a Wave
Amplitude = wave’s height = measure from 0 to the crest
Wavelength = λ = distance between crests = measured in meters
Frequency = ν = number of wave cycles to pass a given point per unit time = measured in hertz (Hz) or (s-1)

3. Electromagnetic radiation: λ x ν = c, the speed of light
Includes radio waves, microwaves, infrared waves, visible light, UV, X-rays, and gamma rays
All electromagnetic radiation travels at the speed of light, c, in a vacuum
c = x 108 m/s

4. Electromagnetic spectrum

5. Electromagnetic spectrum

6. Calculating the wavelength of light
Calculate the wavelength of light emitted by sodium lamps if the frequency of the radiation is 5.10 x 1014 s-1.

7. Calculating the wavelength of light
Known
c = x 108 m/s
ν = frequency = 5.10 x 1014 s-1
Unknown
λ = wavelength = ?

8. Calculating the wavelength of light

9. Calculating the wavelength of light
What is the frequency of radiation with a wavelength of 5.00 x 10-8 m? In what region of the electromagnetic spectrum is this radiation?

10. Calculating the wavelength of light
Known
c = x 108 m/s
λ = wavelength = 5.00 x 10-8 m
Unknown
ν = frequency = ?

11. Calculating the wavelength of light

12. Einstein and de Broglie
Einstein showed light can behave like a particle
Light particles are called photons (they are like packets of energy)
de Broglie showed matter particles can behave like waves
Wavelike properties of electrons are used in electron microscopes because they have smaller wavelengths than visible light