quantum mechanical model and electron configurations
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Quantum Mechanical Model and Electron Configurations. 5.1. The Quantum Mechanical Model. - PowerPoint PPT PresentationTRANSCRIPT
Quantum Mechanical Model and Electron Configurations
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)
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.
5.1
Atomic Orbitals Different atomic orbitals are denoted by letters.
The s orbitals are spherical, and p orbitals are dumbbell-shaped.
5.1
Atomic Orbitals Four of the five d orbitals have the same shape
but different orientations in space.
5.1
Atomic Orbitals The numbers and kinds of atomic orbitals depend
on the energy sublevel.
5.1
Number of Orbitals in Each Sublevel
Sublevel Number of Orbitals
Number of Electrons in each Orbital
Number of Electrons in Each Sublevel
s 1 2 2
p 3 2 6
d 5 2 10
f 7 2 14
Electron Configurations Electron Configurations
What are the three rules for writing the electron configurations of elements?
5.2
Slide 9 of 20
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Electron Arrangement in Atoms
> 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.
5.2
Slide 10 of 20
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Electron Arrangement in Atoms
> 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.
5.2
Slide 11 of 20
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Electron Arrangement in Atoms
> 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.
5.2
Slide 12 of 20
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Electron Arrangement in Atoms
>
Slide 13 of 20
© Copyright Pearson Prentice Hall
Electron Arrangement in Atoms
>
© Copyright Pearson Prentice Hall
Slide 14 of 20
Use each type of diagram to write out configuration.
for Conceptual Problem 1.1
Problem Solving 5.9 Solve Problem 9 with the help of an interactive guided tutorial.
DO SHORT HAND AND ORBITAL DIAGRAM
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
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
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…
Practice: Electron Configuration of Ions
Cl-1
O-2
Na+1
Ca+2
Do short hand and orbital diagram.
Weird Stuff http://www.newscientist.com/blogs/nstv/
2011/09/one-minute-physics-is-schrodingers-cat-dead-or-alive.html
END OF SHOW