C. Johannesson IV. Electron Configuration (p. 105 - 116, 128 - 139) Ch. 4 - Electrons in Atoms.
C. Johannesson III. Quantum Model of the Atom (p. 98 - 104) Ch. 4 - Electrons in Atoms.
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Transcript of C. Johannesson III. Quantum Model of the Atom (p. 98 - 104) Ch. 4 - Electrons in Atoms.
C. Johannesson
III. Quantum Model
of the Atom(p. 98 - 104)
Ch. 4 - Electrons in Atoms
C. Johannesson
A. Electrons as WavesLouis de Broglie (1924)
Applied wave-particle theory to e-
e- exhibit wave properties
QUANTIZED WAVELENGTHS
C. Johannesson
A. Electrons as WavesQUANTIZED WAVELENGTHS
C. Johannesson
A. Electrons as Waves
EVIDENCE: DIFFRACTION PATTERNS
ELECTRONSVISIBLE LIGHT
C. Johannesson
B. Quantum MechanicsHeisenberg Uncertainty Principle
Impossible to know both the velocity and position of an electron at the same time
C. Johannesson
B. Quantum Mechanics
σ3/2 Zπ
11s 0
eΨ a
Schrödinger Wave Equation (1926) finite # of solutions quantized energy
levels defines probability of finding an e-
C. Johannesson
B. Quantum Mechanics
Radial Distribution CurveOrbital
Orbital (“electron cloud”) Region in space where there is 90%
probability of finding an e-
C. Johannesson
C. Quantum Numbers
UPPER LEVEL
Four Quantum Numbers: Specify the “address” of each electron in
an atom
C. Johannesson
C. Quantum Numbers
1. Principal Quantum Number ( n )
Energy level
Size of the orbital
n2 = # of orbitals in the energy level
C. Johannesson
C. Quantum Numbers
s p d f
2. Angular Momentum Quantum # ( l ) Energy sublevel Shape of the orbital
C. Johannesson
C. Quantum Numbers
n = # of sublevels per leveln2 = # of orbitals per levelSublevel sets: 1 s, 3 p, 5 d, 7 f
C. Johannesson
C. Quantum Numbers
3. Magnetic Quantum Number ( ml ) Orientation of orbital Specifies the exact orbital
within each sublevel
C. Johannesson
C. Quantum Numbers
px py pz
C. Johannesson
C. Quantum Numbers
Orbitals combine to form a spherical shape.
2s
2pz2py
2px
C. Johannesson
C. Quantum Numbers
4. Spin Quantum Number ( ms ) Electron spin +½ or -½ An orbital can hold 2 electrons that spin
in opposite directions.
C. Johannesson
C. Quantum Numbers
1. Principal # 2. Ang. Mom. # 3. Magnetic # 4. Spin #
energy levelsublevel (s,p,d,f)orbitalelectron
Pauli Exclusion Principle No two electrons in an atom can have
the same 4 quantum numbers. Each e- has a unique “address”:
C. Johannesson
Feeling overwhelmed?
Read Section 4-2!