1. 5.2 Properties of Light Our goals for learning What is light?
What is the electromagnetic spectrum?

2. What is light? Light can act either like a wave or like a particle
A wave is a pattern of motion that can carry energy without carrying matter along with it

3. Light: Electromagnetic Waves
A light wave is a vibration of electric and magnetic fields
Light interacts with charged particles through these electric and magnetic fields

4. wave speed = wavelength x frequency
Properties of Waves
amplitude
Wavelength is the distance between two wave peaks
Frequency is the number of times per second that a wave vibrates up and down
Wave Equation: v =  x f
wave speed = wavelength x frequency

5. What’s the relationship between wavelength and frequency?
They are inversely related, as frequency increases wavelength decreases; as wavelength increases frequency decreases.

6. Particles of Light Particles of light are called photons
Each photon has a wavelength and a frequency
The energy of a photon depends on its frequency

7. Energy of light Wave Equation for light : c = l x f
 = wavelength
f = frequency
c = 3.00 x 108 m/s (speed of light)
photon energy:
E = h x f
E = energy
h = x Js

8. What is the electromagnetic spectrum?
The entire range of wavelengths of light is called the electromagnetic spectrum.

10. The colors of visible light are:
R – O – Y – G – B – I – V
700 nm – 400 nm

11. Thought Question The higher the photon energy…
the longer its wavelength.
the shorter its wavelength.
energy is independent of wavelength.

12. Thought Question The higher the photon energy…
the longer its wavelength.
the shorter its wavelength.
energy is independent of wavelength.