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Chapter 7: 1-3

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Electron Orbitals and Subshells

Chapter 7: 1-3 Homework

Reading Preparation

Textbook assignment: Read Kotz and Triechel, Chemistry and Chemical Reactivity Chapter 7: Sections 1-3.

Study Notes

7.1 The Pauli Exclusion Principle: Continuing our principle that the quantum number configuration for each electron is unique, we realize that the direction of spin limits the number of electrons in a given orbital to two, which differ from each other only in that one is spin-up, the other spin-down.

7.2 Subshell Energies: We are now in a position to compare the forces holding electrons in place around the atom and the amounts of energy required to pull electrons entirely away from an atom. Since this process leaves an ionized atom behind, the energy is called the ionization energy; it can be experimentally determined for each electron in the shell for atoms at a given temperature.

7.3 Electron Configurations: We now combine the electron orbital information (in terms of quantum numbers) with the spin information, the Pauli Exclusion principle, and Hund's rule (maximize the number of unpaired electrons) to generate descriptions of the electron configurations possible for atoms in a ground state or an excited state. Complications arise for transition elements: study this part!

There are no equations for these sections.

Web Lecture

Read the following weblecture before chat: Electron SubShells

Study Activity

Videos for Chapter 7: Electron Configurations

Review the Videos at Thinkwell Video Lessons.

  • Under "Electron Configurations and Periodicity: Electron Spin and the Pauli Exclusion Principle"
    • Understanding Electron Spin
    • Electron Shielding

Use the It's Elementary to review how to write the correct description for electrons in the ground state.

  • Read the introduction It's Elementary... for a Mad Scientist.
  • Read Energy Levels and Orbitals.
  • Read Notation Levels.
  • Play the Building Elements Game to build four elements.

Chat Preparation Activities

Chapter Quiz

Lab Work

LAB #5 GUIDED INQUIRY: Using two-phase chromatography separation of mixtures -- Phase I

How can we use light absorption and color to identify and separate substances? Using the resources below to explore your options, design an experiment using chromatography techniques to separate dyes in common household substances, then interpret your data terms of the relative strength of interactions among and between the components. List your equipment and materials, and outline your process and the data you will collect.