Transcript Chapter 4-2 The Quantum Model of the Atom

Chapter 4-2
The Quantum Model of the
Atom
By: Astrid Rodriguez
Ray Franco
Randy Cooper
Grace Martinez
Rick Perez
Electrons as Waves
 In 1924 Louis de Broglie found that electrons could
have dual wave particle nature.
 Broglie suggested that electrons be considered
waves confined to the space around an atomic
nucleus.
 Electrons can have electron waves only at specific
frequencies.
 Diffraction refers to the bending of a wave as it
passes by the edge of an object, such as the edge of
an atom in a crystal.
 Interference between electron beings occur when
waves over lap. It results in the reduction of energy
in some areas and the increase in others.
The Heisenberg Uncertainty
Principle
Proposed by German
theoretical physicist
Werner Heisenberg in
1927.
Principal states that it is
impossible to determine
simultaneously both the
position and velocity of an
electron or any other
particle.
It is one of the
fundamental principles of
our present understanding
of light and matter.
The Schrödinger Wave Equation
Austrian physicist Erwin Schrödinger developed an
equation that treated electrons in atoms as waves.
With the Heisenberg Uncertainty Principle, the
Schrödinger Wave Equation laid the foundation for
quantum theory.
Quantum theory describes mathematically the wave
properties of electrons and other very small
particles.
Orbitals is a three-dimensional region around
the nucleus that indicates the probable
location of an Electron.
Erwin Schrödinger
Atomic Orbitals and Quantum
Numbers
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Quantum numbers specify the properties of atomic orbitals
and the properties of electrons in orbitals.
Principal quantum number, symbolized by n,indicates the main
energy level occupied by the electrons. As the energy level
increases the distance from the nucleus increases
Angular momentum quantum number, symbolized by l indicates
the shape of the orbital.
Magnetic quantum number, symbolized by m, indicates the
orientation of an orbital around the nucleus.
Spin quantum number, has only two possible values (+1/2, 1/2) which indicates the two fundamental spin states of an
electron.
Quantum Number Relationships in Atomic Structure
Main energy level
(n)
Sublevels in main
energy level
1
s
2
Number of orbital per
sublevel
Number of electrons
per sublevel
Number of electrons
in energy level
1
2
2
s
p
1
3
2
6
8
3
s
p
d
1
3
5
2
6
8
18
4
s
p
d
f
1
3
5
7
2
6
8
10
14
32
Bibliography
Modern Chemistry Book
printed 2005
Published by Holt, Rinehart and Winston
Area printed Dallas, Texas
 Britannica Online. Encyclopedia Britannica
Inc. November 6, 2007
