1. What things were wrong with Bohr’s atomic model?
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2. The Electron
Chapter 5
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3. Revising the Atomic Model
5.1
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4. What’s wrong with Bohr’s model?
Electrons don’t move in perfect circles!
What did Louis de Broglie say electrons behaved like?
Energy levels have sub-levels
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5. The Quantum Mechanical Model
Does not specify the path an electron takes around the nucleus
Heisenberg Uncertainty Principle
What is the probability of an electron being in a certain place at a certain time?
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6. The Quantum Mechanical Model
Each energy level can be broken down into sublevels
Sublevels are denoted by letter
Each of those sublevels has a unique amount of orbitals
These orbitals describe where the electron is most likely to be found
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7. Atomic Orbitals Four different types of sublevel s, p, d, f
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8. Atomic Orbitals s – 1 orbital p – 3 orbitals d – 5 orbitals
f – 7 orbitals
Each orbital can hold at maximum two electrons
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10. How do we know where electrons go within these sublevels and their orbitals?
Aufbau Diagram
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11. How do we know where electrons go within these sublevels and their orbitals?
Orbital Filling Diagrams
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12. Filling in these diagrams
Depict electrons as arrows
Can only put TWO arrows in each orbital box
One pointing up, one pointing down
The direction of the arrow shows which way the electron is spinning
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13. Three rules to filling out Aufbau diagrams and orbital filling diagrams
Aufbau Principle
Electrons occupy the orbitals of lowest energy first
In other words, fill 1s in completely before you fill in 2s
Pauli Exclusion Principle
An orbital can have at maximum two electrons
Those electrons must have opposite spin
Hund’s Rule
Maximize the spin of the sublevel
In other words, put one electron in every orbital pointing up before filling the orbitals completely
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15. Practice! What does the Aufbau diagram for Carbon look like?
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16. Practice! What does the Aufbau diagram for Neon look like?
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17. Practice! What does the Aufbau diagram for Calcium look like?
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18. Is there an easier way to write these out?
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19. Electron Configuration
Condensed, shorthand version of an Aufbau diagram
Simply write out the name of the sublevel with the number of electrons in that sublevel subscripted
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