1. Section 1 Characteristics of Light
Chapter 14
Objectives
Identify the components of the electromagnetic spectrum.
Calculate the frequency or wavelength of electromagnetic radiation.
Recognize that light has a finite speed.
Describe how the brightness of a light source is affected by distance.

2. Electromagnetic Waves
Section 1 Characteristics of Light
Chapter 14
Electromagnetic Waves
An electromagnetic wave is a wave that consists of oscillating electric and magnetic fields, which radiate outward from the source at the speed of light.
Light is a form of electromagnetic radiation.
The electromagnetic spectrum includes more than visible light.

3. The Electromagnetic Spectrum
Section 1 Characteristics of Light
Chapter 14
The Electromagnetic Spectrum

4. The Electromagnetic Spectrum, continued
Section 1 Characteristics of Light
Chapter 14
The Electromagnetic Spectrum, continued
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5. Electromagnetic Waves, continued
Section 1 Characteristics of Light
Chapter 14
Electromagnetic Waves, continued
Electromagnetic waves vary depending on frequency and wavelength.
All electromagnetic waves move at the speed of light. The speed of light, c, equals
c = 3.00  108 m/s
Wave Speed Equation
c = fl
speed of light = frequency  wavelength

6. Electromagnetic Waves
Section 1 Characteristics of Light
Chapter 14
Electromagnetic Waves

7. Electromagnetic Waves (visible light)
Section 1 Characteristics of Light
Chapter 14
Electromagnetic Waves (visible light)
Objects are either luminous or illuminated.
Luminous objects produce (emit) light
Illuminated objects reflect light

8. Electromagnetic Waves, continued
Section 1 Characteristics of Light
Chapter 14
Electromagnetic Waves, continued
Illuminance decreases as the square of the distance from the source.
The rate at which light is emitted from a source is called the luminous flux and is measured in lumens (lm).

9. Wave-Particle Duality
Section 1 Characteristics of Light
Chapter 14
Wave-Particle Duality
Light behaves as both a wave and a particle. This notion is called the wave-particle duality.
A photon is a unit or quantum of light. Photons can be thought of as particles of electromagnetic radiation that have zero mass and carry one quantum of energy.