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Transcript
Bohr & Schrödinger
The Bohr Model
Recall Bohr’s model of the atom:
Ar
2
8
8
18
Bohr’s model of the atom was famous because it
could explain the bright line spectrum
continuous
The spectrum of white light is _________________,
it shows all the colours of the rainbow
The spectrum of energized gas is
discontinuous it shows _________________.
discrete bands
_________________,
E1
Ground state
E1
st excited
1Ground
state
state
E1
Ground state
packet of light
1st excited state
photon
E1
Ground state
E2
Ground state
2nd excited state
E2-E1
E2
1st excited state
Ground state
2nd excited state
E2
Ground state
When particles are exposed to energy
• ground state (lowest energy state) atoms
absorb specific energy and become “excited”
– an electron moves to a higher shell
• excited atoms then release the energy at
specific frequencies to get back to ground
state
– the electron moves back to its original shell,
emitting a photon (packet of light)
• the difference between two particular energy
levels is called the quantum
• the lines in the spectrum are produced when
electrons de-excite
quantum
Bohr’s model was proven significantly wrong in
2 ways:
– electrons don’t revolve around the nucleus
in circles
– the model can only predict energies H
Dalton
Thomson
Rutherford
Bohr
Schrödinger
Recap
What does “ground state” refer to?
A.
B.
C.
D.
A hydrogen atom
Lowest energy
energy state
stateof
ofan
anatom
atom
Lowest
Highest energy state of an atom
When the atom is on the ground
Recap
How does an electron become “excited?”
A. The atom it resides in reacts with another
atom
B. It absorbs energy and jumps shells
C. It absorbs
absorbs specific
specific amounts
amountsof
ofenergy
energyand
and
jumps shells
shells
D. When it sees a particle of opposite charge
Recap
What is a photon?
A.
B.
C.
D.
A packet
packet of
of light
light
An excited proton
An excited electron
A Chinese wonton stuffed with Vietnamese
noodles
White Light Spectrum
Emission Spectrum of H
Recap
What is an orbital?
A.
B.
C.
D.
The path an electron takes around the nucleus
Lobes
The shape of the nucleus
Mathematical
Mathematical description
description(probability)
(probability)ofof
where to find
find an
an electron
electronin
inan
anatom
atom
8.2 - Quantum Mechanics:
Schrödinger’s atomic model
Schrödinger’s model describes the probability of
where to find an electron in an atom
• orbital: the region of space around a nucleus
where an electron can be found
• orbitals are described by quantum numbers
Quantum
Number
1st or principal
quantum
number (n)
2nd quantum
number (l)
3rd quantum
number (m)
4th quantum
number (ms)
Symbols
What does it mean?
1, 2, 3 … Size and energy level
2s
Quantum
Number
1st or principal
quantum
number (n)
2nd quantum
number (l)
3rd quantum
number (m)
4th quantum
number (ms)
Symbols
What does it mean?
1, 2, 3 … Size and energy level
s, p, d, f Orbital shape
s orbital
p orbital
d orbital
f orbital
Quantum
Number
1st or principal
quantum
number (n)
2nd quantum
number (l)
3rd quantum
number (m)
4th quantum
number (ms)
Symbols
What does it mean?
1, 2, 3 … Size and energy level
s, p, d, f Orbital shape
x, y, z
Orbital orientation
Quantum
Number
1st or principal
quantum
number (n)
2nd quantum
number (l)
3rd quantum
number (m)
4th quantum
number (ms)
Symbols
What does it mean?
1, 2, 3 … Size and energy level
s, p, d, f Orbital shape
x, y, z
Orbital orientation
½ or -½ Electron spin
Each energy level has a specific set of orbitals and each one
represents where a maximum of 2 electrons can be found.
Orbital Type
Begins at n=
# of Orbitals in
a Subshell
s
p
d
f
1
2
3
4
1
3
5
7
Maximum # of
Electrons in
Subshell
2
6
10
14