Transcript JJ Thomson - WaylandHighSchoolChemistry

Atomic Theory
Agenda
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Review Elements
What do you know about the atom?
(whiteboard review)
Song – Atomic Theory Polka
Reading 4.2 & 4.3
Notes
Zn
zinc
Sc
scandium
Fe
iron
Mn
manganese
V
vanadium
Ni
nickle
Cr
chromium
Co
cobalt
Ti
titanium
Cu
copper
What do you know about the atom?
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Who was Democritus?
What did he contribute to the model of the
atom?
Who came up with the atomic theory?
What were his four points?
Atomic Theory Polka
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Dalton, Thomson, Rutherford and Bohr.
Schrödinger and Heisenberg, and many, many
more. Used their brains to venture in the
realm of inner space and found the world of
the atom was a weird and wondrous place.
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Dalton did experiments and said, “I think it’s
clear, atoms are tiny indestructible spheres.”
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Thomson worked with cathode rays and said,
“I disagree. A plum-pudding model makes
much more sense to me.”
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A new chapter in atomic theory started to
unfold when Rutherford played around with
atoms made of gold. When a few of his alpha
particles came bounding back, he
hypothesized a nucleus had knocked them off
the track.
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Dalton, Thomson, Rutherford and Bohr.
Schrödinger and Heisenberg, and many, many
more. Used their brains to venture in the
realm of inner space and found the world of
the atom was a weird and wondrous place.
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Bohr saw spectral lines for hydrogen and said,
“It seems to me.. Electrons move in orbits
with specific energies.”
electron
neutron
proton
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Heisenberg said, “Forget it, there’s no way to
know the orbit or a path, where the electron’s
gonna go.”
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Schrödinger used lots and lots of fancy
mathematics, and made a model of the atom
based on quantum mechanics. It has orbitals
and those are based on probability. The atom
is a fuzzy blob of pure uncertainty.
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Dalton, Thomson, Rutherford and Bohr.
Schroedinger and Heisenburg, and many,
many more. Used their brains to venture in
the realm of inner space and found the world
of the atom was a weird and wondrous place.
Read 4.2 – 4.3 in a 6 inch voice
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Fill out the study guide as you read in
complete sentences.
Atomic Theory Part II
Date:
JJ Thomson
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Found electron
Used cathode ray tube
“Plum Pudding” or “Chocolate Chip Cookies”
model
Robert Millikan
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Determined the electrical charge of electron
“Oil Drop Experiment”
Still plum pudding model
Eugen Goldstein
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Found the proton
Still plum pudding model
Ernest Rutherford
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Found nucleus
Gold foil experiment
Atom is mostly empty space – first nuclear model
James Chadwick
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Found neutron
Shot alpha particles at Be nucleus
Nucleus is made of two particles
Niels Bohr
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Planetary model
Proposed electrons have a set amount of energy putting them
in different energy levels, or orbits around the nucleus.
Electrons can change energy levels; higher energy levels are
further from the nucleus.
electron
neutron
proton
Heisenberg’s uncertainty principle
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Heisenberg’s uncertainty principle: cannot
know exactly both the velocity and position of
electron at the same time.
Like trying to catch a helium balloon in the
dark.
Schrödinger
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Electrons move like moths around a light –
unpredictable.