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Chapter 6: 1-3

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Electrons, Orbitals, and Electromagnetic Radiation

Chapter 6: 1-3 Homework

Reading Preparation

Textbook assignment: Read Kotz and Triechel, Chemistry and Chemical Reactivity Chapter 6 Sections 1 to 3.

Study Notes

6.1 Electromagnetic radiation (EM) is light, and light is a wave. The fundamental relationship of all waves is described by speed of wave = frequency * wavelength.

6.2 The energy carried by a single photon of light depends on the frequency (which in turn depends on the speed and wavelength): E = h*frequency = h * speed/wavelength, where h is Planck's constant.

6.3 When electrons change energy states and move between orbitals around an atom, they emit or absorb light with energy equal to the change. Bohr related the change to the energy level by the Rydberg constant, R. Electrons in the ground state have the lowest amount of energy possible. Electrons in excited states have absorbed the precise amount of energy required to make the jump to their excited state.

Important Equations and Conversion Factors

Light Wave Relationships c   =   λ υ c: speed of wave
λ: wavelength
ν: frequency
Planck Equation E   =   h υ   =   hc λ E: photon energy
h: Planck constant
ν: frequency
c: speed of light
λ: wavelength
Rydberg Equation 1 λ   =   R ( 1 n f 2   1 n i 2   ) λ: wavelength
R: Rydberg constant
nf: Final energy level
ni: Initial energy level
Bohr Energy for Hydrogen electrons E n   =   hcR ( 1 n 2   ) En: Electron energy at level n
h: Planck constant
R: Rydberg constant
c: speed of light
n: energy level

Web Lecture

Read the following weblecture before chat: Electromagnetic Radiation and Photons

Study Activity

Videos for Chapter 6: The Structure of Atoms

Review the Videos at Thinkwell Video Lessons.

  • Under "ATOMS, MOLECULES, AND IONS: Atomic Structure"
    • Modern Atomic Structure
  • Under "MODERN ATOMIC THEORY: Electromagnetic Radiation and the Idea of Quantum"
    • The Wave Nature of Light
    • Absorption and Emission
    • The Ultraviolet Catastrophe
    • The Photoelectric Effect
    • The Bohr Moddel
Simulation activity

Use the simulation below to explore what happens when you change the wavelength and tension on a string. Be sure that you understand how speed, wavelength, and frequency are related.

Chat Preparation Activities

Chapter Quiz

Lab Work

LAB #4 GUIDED INQUIRY: Measuring reaction rates for photosensitive reactions -- Phase I

Working with your teacher and classmates, design a set of standard concentrations of iodine to act as a reference, and propose method to calibrate concentrations of iodine solution matching your standards. You will use the standards you create to measure the change in concentration during timed reactions of oxalate and iodine conducted under different amounts of light. You will need to identify the materials required for your solutions, and a set of useful concentrations, and describe how you will generate each concentration level.