1. Chapter 4 The Wave Description of Light
Section 1 The Development of a New Atomic Model
Chapter 4
The Wave Description of Light
Electromagnetic radiation - form of energy that exhibits wavelike behavior as it travels through space.
Electromagnetic spectrum - all the forms of electromagnetic radiation together.

2. Electromagnetic Spectrum
Section 1 The Development of a New Atomic Model
Chapter 4
Electromagnetic Spectrum

3. Electromagnetic Spectrum
Visual Concepts
Chapter 4
Electromagnetic Spectrum
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Visual Concept

4. Chapter 4 Properties of Light
Section 1 The Development of a New Atomic Model
Chapter 4
Properties of Light
Wavelength () - distance between corresponding points on adjacent waves.
Frequency (v) - number of waves that pass a given point in a specific time, usually one second.

5. c = v Chapter 4 Properties of Light
Section 1 The Development of a New Atomic Model
Chapter 4
Properties of Light
Frequency and wavelength are mathematically related to each other:
c = v
c - speed of light (in m/s)
 - wavelength of the electromagnetic wave (in m)
v - frequency of the electromagnetic wave (in s1).

6. Wavelength and Frequency
Section 1 The Development of a New Atomic Model
Chapter 4
Wavelength and Frequency

7. The Photoelectric Effect
Section 1 The Development of a New Atomic Model
Chapter 4
The Photoelectric Effect
Photoelectric effect - emission of electrons from a metal when light shines on the metal.
The Particle Description of Light
Quantum - minimum quantity of energy that can be lost or gained by an atom.

8. Chapter 4 Photoelectric Effect
Section 1 The Development of a New Atomic Model
Chapter 4
Photoelectric Effect

9. Chapter 4 Photoelectric Effect Visual Concepts
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Visual Concept

10. E = hv Chapter 4 The Particle Description of Light
Section 1 The Development of a New Atomic Model
Chapter 4
The Particle Description of Light
E = hv
E - energy, in joules, of a quantum of radiation
v - frequency, in s−1, of the radiation emitted
h – constant known as Planck’s constant; h =  1034 J• s.

11. Chapter 4 The Particle Description of Light
Section 1 The Development of a New Atomic Model
Chapter 4
The Particle Description of Light
Photon - particle of electromagnetic radiation having zero mass and carrying a quantum of energy.

12. Quantization of Energy
Visual Concepts
Chapter 4
Quantization of Energy
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Visual Concept

13. The Hydrogen-Atom Line-Emission Spectrum
Section 1 The Development of a New Atomic Model
Chapter 4
The Hydrogen-Atom Line-Emission Spectrum
Ground state - lowest energy state of an atom
Excited state - state in which an atom has a higher potential energy than it has in its ground state
Line-emission spectrum - four bands of light separated as hydrogen gas passes through a prism

14. Hydrogen’s Line-Emission Spectrum
Section 1 The Development of a New Atomic Model
Chapter 4
Hydrogen’s Line-Emission Spectrum

15. Bohr Model of the Hydrogen Atom
Section 1 The Development of a New Atomic Model
Chapter 4
Bohr Model of the Hydrogen Atom
Orbits - paths in which electrons circle the nucleus of an atom
The energy of the electron is higher when the electron is in orbits that are successively farther from the nucleus.

16. Chapter 4 Bohr Model of the Atom Visual Concepts
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Visual Concept

17. Bohr Model of the Hydrogen Atom
Section 1 The Development of a New Atomic Model
Chapter 4
Bohr Model of the Hydrogen Atom
Emission - electron falls to a lower energy level, a photon is emitted.
Absorption - Energy must be added to an atom in order to move an electron from a lower energy level to a higher energy level.

18. Photon Emission and Absorption
Section 1 The Development of a New Atomic Model
Chapter 4
Photon Emission and Absorption

19. Comparing Models of the Atom
Visual Concepts
Chapter 4
Comparing Models of the Atom
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Visual Concept