Quantum Theory & Electron Configuration
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Wavelength () - length of one _____________________ wave measured in m, cm, or nm
o In light it tells us which __________________ it is
Frequency () - __________________ of waves that pass a _______________ during a certain time period,
o ________________ (Hz) = 1/s
Amplitude (A) - distance from the _______________ to the trough or ___________________
o how much ______________ the wave is carrying. It is the height of the wave. It is measured in _____________.
In SOUND it tells us how LOUD it is. In LIGHT it tells how ________________ it is.
Wave Nature of Light (& Particles)
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To understand the electronic structure of atoms we must understand ____________ and how it is _______________ or
absorbed by substances.
We will examine visible light a type of _________________ _________________ (EM) which carries (radiant) energy
through space (speed of light) and exhibits _________________ behavior.
Also need to think of light as ___________________, to help understand how EM radiation and atoms interact
Characteristics of EM radiation
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Move through a _______________________ at the ‘speed of light’ 3.00 x 108 m/s
Behaves like _____________ that move through water, which are the result of a transfer of _____________ to the water
(from a stone), expressed as up and down movement of water
Both ___________________ and _______________ properties
Wave Speed = (distance between wave peaks) x (frequency)
=
(_______________)
x (frequency)
EM radiation moves through a vacuum at the “speed of light” 3.00 x 108 m/s also called c.
A _____________ energy wave (infrared and red) has a longer wavelength() and lower frequency(f)
A _____________ energy wave (blue - violet) has a shorter wavelength() and higher frequency(f).
EM Spectrum
*Frequency & wavelength are inversely proportional
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c:
:
:
_______________________________ (3.00  108 m/s)
_______________________________ (m, nm, etc.)
_______________________________ (Hz)
EX: Find the frequency of a photon with a wavelength of 434 nm.
Quantum Theory:
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Planck (1900)
o Observed - emission of light from _________ __________________
o Concluded - energy is emitted (_______________ or ______________) in small, specific amounts (quanta)
o Quantum - smallest ________________ packet that can be emitted or absorbed as _____ radiation by an atom.
Planck proposed that the energy, E, of a single quantum energy packet equals a____________ (h) times its frequency
The energy of a photon is __________________ to its frequency.
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o
E: _______________ (J, joules)
o
h:______________(6.6262  10-34 J·s)
o
: ___________________
EX: Find the energy of a red photon with a frequency of 4.57  10 Hz.
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Planck (1900)
Classic Theory
o
o
o
Quantum Theory
Energy is always emitted or absorbed in whole number
of hv, such as hv, 2 hv, 3 hv, 4hv, …. The
allowed energies are quantized, that is their values are
to certain
.
The notion of quantized rather than continuous energies is strange. Consider a ramp and a staircase, on a ramp you can
____________ the length your steps and energy used on the walk up. When walking up steps you must exert exactly the
__________
_
amount of
needed to reach the next step. Your steps on steps are quantized, you
step between them.
Einstein (1905)
Observed – photoelectric effect
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Dispersed light falls on metal samples, the different frequencies produce different energetic photoelectrons
Concluded - light has properties of both __________ and __________________ (photons)
“wave-particle ________________”
- particle of light that carries a quantum of energy
Used planck’s quantum theory to deduced that:_________________________________
Bohr Model of the Atom
Line –Emission Spectra
o
Set of ___________________ of EM waves emitted by atoms an element when they ______________ electrical
energy, eˉ get excited, become somewhat unstable and release energy in the form of light
Bohr Model
o
e- exist only in ___________ with specific amounts of energy called energy levels
Therefore…
o e- can only _______ or ________ certain amounts of energy
o only certain _______________ are produced
o Ground state: ____________ allowable atomic electron energy state
o _______________ state: any higher energy state
o Energy of photon depends on the ____________________ in energy levels
o Bohr’s calculated energies matched the IR, visible, and UV lines for the H atom
Each element has a ________________ bright-line emission spectrum.
o
“Atomic Fingerprint”
Quantum Model of the Atom
Electrons as Waves
o Louis de Broglie (1924)
o Proposed eˉ in their _________________ behave like a ______________
o Wavelength of an eˉ depends on its ___________(m) and its velocity (v):
λ = _h _
mv
Quantum Mechanics
Heisenberg Uncertainty Principle
o Impossible to know both the ______________ and _______________ of an electron at the same time
o Attempting to observe an electron’s position changes its _____________________ & attempting to observe an
electrons momentum changes its __________________. Therefore electrons cannot be locked into well-defined
circular orbits around the nucleus.
Schrödinger Wave Equation (1926)
o proposed a wave equation incorporating both the _______ and _____________ nature of the electron.
o The result of the equation, wave functions, shows the _________________ that an electron will be in a certain region
of space at a given instant. This electron ________________ is represented by a distribution of dots which represents
where electrons are located about 90% of the time
o finite # of solutions  __________________ energy levels
o defines probability of finding an ___________________
o _________________(“electron cloud”)
o a specific distribution of electron _______________ in space.
o Each orbital has a characteristic _____________ and ______________.
Quantum Numbers:
Specify the “__________________” of each electron in an atom
1. Principal Quantum Number (n = 1, 2, 3, …) (see periodic table left column)
o Indicates the relative _______ and __________ of atomic orbitals
o As (____) increases, the orbital becomes larger, the electron spends more time _________________ from
the nucleus
o Each major energy level is called a ______________ energy level
Ex: lowest level = 1 _____________ state,
highest level = 7 _________________ state
2. Energy Sublevel
o Defines the _____________ of the orbital (s, p, d, f)
o # of orbital related to each sublevel is always an ________#
s = 1, p = 3, d = 5, f = 7
o Each orbital can contain at most _____ ________________________
3. Subscripts x, y, z designates ____________________
o Specifies the exact ______________ within each sublevel
4. Spin Quantum Number ( ms )
o Electron spin  _________ or _________
o An orbital can hold 2 electrons that _________ in ________________ directions.
Pauli Exclusion Principle
o A maximum of 2 electrons can occupy a single atomic orbital
o Only if they have opposite spins
1. Principal #
 _________________________
2. Energy sublevel  __________________________
3. Orientation
 __________________________
4. Spin #
 __________________________
Electrons in the Atom: Electron Configuration
General Rules
o
Aufbau Principle
o Electrons fill the _____________energy orbitals first.
o “Lazy Tenant Rule”
o Hund’s Rule
o Within a sublevel, place ___________ e- per orbital before _____________________ them.
o “Empty _______ _____________ Rule”
Notation
Orbital Diagram
Oxygen
Longhand Configuration of S
o
16 e-
Valence electrons: determine _________________ properties of that element & are the electrons in the atoms
_____________________ orbital
Shorthand Configuration:
o
o
Core e-: Go up one ________ and over to the ______________ _______________.
Valence e-: On the next row, fill in the # of _______________ in each sublevel.
Ex: Germanium : _____________________________________________
Stability: *Full ___________ level
*Full _____________________ (s, p, d, f)
*Half Full ______________________
Electron Configuration Exceptions:
Copper: Expect: _____________________________
o
o
Actually:_____________________________
Copper gains ____________________ with a full ____-sublevel.
Chromium: Expect: _____________________________
o
Actually:_____________________________
Chromium gains stability with a half-full d-sublevel.
Ion Formation
o
o
Atoms gain or lose ________________ to become more ______________.
o
________electronic with the Noble Gases. (iso=same)
Ion Electron Configuration
o
Write the e- config for the closest _____________ Gas
o
EX: Oxygen ion  O2-  Ne
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