chapter – 6 oct 24, 2011 part - b
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Chapter – 6 Oct 24, 2011 Part - B. The legends of physical sciences. The De Broglie’s Equation. In 1924 Louis De Broglie proposed that electrons do not behave like solid particles, but they behave like waves. - PowerPoint PPT PresentationTRANSCRIPT
Chapter – 6 Oct 24, 2011 Part - BChapter – 6 Oct 24, 2011 Part - B
The legends of physical sciencesThe legends of physical sciences
The De Broglie’s Equation
In 1924 Louis De Broglie proposed that
electrons do not behave like solid
particles, but they behave like waves.
Louis De Broglie(1892 – 1987)
De Broglie suggested that the wavelength
of a particle of mass m moving at speed v
is,
h = plank’s constantmvh
This relation provides the link between the
description of electron as a particle and as a wave
The Schrodinger’s Wave Equation
developed this idea and solved
wave equations to make predictions
about where an electron may be
found in an atom.
Edwin Schrodinger(1887 – 1961)
Schrodinger’s wave equations , when solved, identifies a region in space around the nucleus where there is a 90% probability of finding an electron with a specified energy.
The Heisenberg Uncertainty Principle
When you try to observe the wave nature of the
electron, you cannot observe its particle nature
and vice versa, we cannot locate electrons and
simultaneously observe their wave nature.
it is impossible to simultaneously measure the position and momemtum of an electron with exactitude.
Werner Heisenberg 1901-1976
Indeterminacy of Electrons
A baseball follows a well-defined
trajectory from the hand of the
pitcher to the mitt of the catcher.
The catcher can see the trajectory
of the ball and predict correctly to
place the mitt in the right place to
catch the ball.
However, electrons do not follow
a fixed path to predict, we can only
have a statistical map when
electrons can be found under a
given set of conditions.
Probability Distribution Map
If the baseball displayed wave-particle duality, the path of the baseball
could not be precisely determined.
The best we could do would be to make a probability distribution map
of where a "pitched" electron will cross home plate.
In the quantum-mechanical model, specific electron orbits are not
appropriate: the electron's movement cannot be known that precisely.
Instead, we map the probability of finding the electron at various
locations outside the nucleus.
The probability map is called an orbital.