1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Objectives Explain the mathematical relationship among the speed, wavelength, and frequency of electromagnetic radiation. Discuss the dual wave-particle nature of light. Chapter 4

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Start of class warm-up Determine the number of protons and neutrons in each of the nuclides below: 1. 2.Lithium-7 3.Calcium-42 4.Iodine-131 Chapter 4

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Properties of Light The Wave Description of Light Electromagnetic radiation is a form of energy that exhibits wavelike behavior as it travels through space. Together, all the forms of electromagnetic radiation form the electromagnetic spectrum. Chapter 4

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Electromagnetic Spectrum Section 1 The Development of a New Atomic Model Chapter 4

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 4 More accurate electromagnetic spectrum

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Properties of Light, continued Wavelength ( ) is the distance between corresponding points on adjacent waves. Frequency (f) is defined as the number of waves that pass a given point in a specific time, usually one second. Chapter 4

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Wavelength and Frequency Section 1 The Development of a New Atomic Model Chapter 4

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Properties of Light, continued Frequency and wavelength are mathematically related to each other: c = f In the equation: –c = speed of light (m/s) – = wavelength (m) –f = frequency (?). Chapter 4

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Do we understand units????????? In the equation below: c = f m/s=m(?) What must the units in question be in order to balance this equation? A.m B.s C.1/s D.1/m Chapter 4

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model Properties of Light, continued –c = 3.00*10 8 m/s – = 1.25*10 -7 m –f = frequency (?) Chapter 4

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 4 Zoom in on visible light

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 4 Zoom in on visible light What wavelengths of visible light have the highest frequency ?

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 The Development of a New Atomic Model The Photoelectric Effect The photoelectric effect refers to the emission of electrons from a metal when light shines on the metal. Chapter 4

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Photoelectric Effect Section 1 The Development of a New Atomic Model Chapter 4