1. Quantum Mechanical Model and Electron Configurations

2. The Quantum Mechanical Model
5.1
The Quantum Mechanical Model
In the quantum mechanical model, the probability of finding an electron within a certain volume of space surrounding the nucleus can be represented as a fuzzy cloud. The cloud is more dense where the probability of finding the electron is high. (Erwin Schrodinger)
The electron cloud of an atom is compared here to photographs of a spinning airplane propeller. a) The airplane propeller is somewhere in the blurry region it produces in this picture, but the picture does not tell you its exact position at any instant. b) Similarly, the electron cloud of an atom represents the locations where an electron is likely to be found.

3. 5.1
Atomic Orbitals
An atomic orbital is often thought of as a region of space in which there is a high probability of finding an electron.
Each energy sublevel corresponds to an orbital of a different shape, which describes where the electron is likely to be found.

4. 5.1
Atomic Orbitals
Different atomic orbitals are denoted by letters. The s orbitals are spherical, and p orbitals are dumbbell-shaped.
The electron clouds for the s orbital and the p orbitals are shown here.

5. 5.1
Atomic Orbitals
Four of the five d orbitals have the same shape but different orientations in space.
The d orbitals are illustrated here. Four of the five d orbitals have the same shape but different orientations in space. Interpreting Diagrams How are the orientations of the dxy and dx2 – y2 orbitals similar? How are they different?

6. 5.1
Atomic Orbitals
The numbers and kinds of atomic orbitals depend on the energy sublevel.

7. Number of Orbitals in Each Sublevel
Number of Electrons in each Orbital
Number of Electrons in Each Sublevel s 1 2 p 3 6 d 5 10 f 7 14

8. Electron Configurations
5.2
Electron Configurations
Electron Configurations
What are the three rules for writing the electron configurations of elements?

9. Electron Configurations
5.2
Electron Configurations
Aufbau Principle
According to the aufbau principle, electrons occupy the orbitals of lowest energy first. In the aufbau diagram below, each box represents an atomic orbital.
This aufbau diagram shows the energy levels of the various atomic orbitals. Orbitals of greater energy are higher on the diagram. Using Tables Which is of higher energy, a 4d or a 5s orbital?

10. Electron Configurations
5.2
Electron Configurations
Pauli Exclusion Principle
According to the Pauli exclusion principle, an atomic orbital may describe at most two electrons. To occupy the same orbital, two electrons must have opposite spins; that is, the electron spins must be paired.

11. Electron Configurations
5.2
Electron Configurations
Hund’s Rule
Hund’s rule states that electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible.

14. Use each type of diagram to write out configuration.

15. for Conceptual Problem 1.1
DO SHORT HAND AND ORBITAL DIAGRAM
Problem Solving 5.9 Solve Problem 9 with the help of an interactive guided tutorial.

16. Ions: Cation Vs. Anion
Ion: an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Cation: Positively Charged Ion
Loses Electrons
Anion: Negatively Charged Ion
Gains Electrons

17. Ion Electron Configurations
What charges do elements tend to have to be stable?
GET OUT PERSONAL PERIODIC TABLES
Charges for Groups 1, 2, 15, 16, 17, 18

18. Octet Rule and Valence Electrons
Atoms follow the octet rule because they always seek the most stable electron configuration.
Valence Electrons: Electrons in outermost shell. How do we find them?
Octet = 8
Elements want to have 8 electrons in their outer shell…

19. Practice: Electron Configuration of Ions
Cl-1
O-2
Na+1
Ca+2
Do short hand and orbital diagram.

20. Weird Stuff

21. END OF SHOW