Electron Configuration

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Electron Configuration

• Contemporary Chemistry
• Mrs. Coyle

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-Electron Configuration-Orbital Filling
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Electron Configuration

• The way electrons are arranged around the nucleus.

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Three rules are used to build the electron
configuration

• Aufbau principle
• Pauli Exclusion Principle
• Hunds Rule

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Aufbau Principle

• Electrons occupy orbitals of lower energy first.

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Pauli Exclusion Principle

• An orbital can hold only two electrons and they
  must have opposite spin.

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Hunds Rule

• In a set of orbitals, the electrons will fill the
  orbitals in a way that would give the maximum
  number of parallel spins.
• Analogy Students could fill each seat of a
  school bus, one person at a time, before doubling
  up.

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Aufbau Diagram for Hydrogen
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Aufbau Diagram for Helium
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Aufbau Diagram for Lithium
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Aufbau Diagram for Beryllium
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Aufbau Diagram for Boron
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Aufbau Diagram for Carbon
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Aufbau Diagram for Nitrogen
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Aufbau Diagram
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B) -Standard and Shorthand Notation -Arrow
Diagram
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Aufbau Diagram for Fluorine
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Standard Notation of Electron Configuration
Example Fluorine
Number of electrons in the sub level 2,2,5
1s2 2s2 2p5
Main Energy Level Numbers 1, 2, 2
Sublevels
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Shorthand Notation

• Use the last noble gas that is located in the
  periodic table right before the element.
• Write the symbol of the noble gas in brackets.
• Write the remaining configuration after the
  brackets.
• Ex Fluorine He 2s2 2p5

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Arrow Diagram
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Blocks in the Periodic Table