Quantum - NOTES
C-2.1 Illustrate electron configurations by using orbital notation for representative elements.
C-2.2 Summarize atomic properties (including electron configuration, ionization energy, electron affinity, atomic size, and ionic size).
Notes/Q’s
Objective: Students will be able to give a state the four quantum numbers and relate them to the electron’s probable location within an atom.
Appetizer:
1. Why are addresses useful? _____________________
Mr. Amedeo Avogadro
6.022 E23 Atom Drive
Mole City, SC 29687
UPPE
_____________________________________________________________________
2. Do any two people in your class have the exact same address?______________
KEY POINT: Each electron will have a specific address in an atom represented by 4
quantum numbers.
A. Electrons as waves

Think about getting a ticket for a concert. Your ticket will
show the level you are on, the section number, the row, and
the seat number.
Louis de Broglie (1924)
 Applied wave-particle theory to e e- exhibit wave properties
B. Quantum mechanics
 Heisenberg Uncertainty Principle
 Impossible to know both the velocity and position
of an electron at the same time


Schrödinger Wave Equation (1926)
 finite # of solutions  quantized energy levels
 defines probability of finding an eOrbital (“electron cloud”)
 Region in space where
there is 90% probability
of finding an e-
In the same way, each electron has 4 unique quantum
numbers that identify its specific seat in the “stadium” we
call the atom.
C. Four Quantum Numbers:
Specify the “address” of each electron in an atom
1. Principal Quantum Number ( n )
 Energy level

Size of the orbital

n2 = # of orbitals in

2n2 = # e- in level the energy level

Corresponds to the period on the P.T.
n
1
2
3
Orbital
4
# of orbitals (n2)
# of e- (2n2)
Quantum - NOTES
Notes/Q’s
2. Angular Momentum Quantum # ( l )
 Energy sublevel

Orbitals combine to form a spherical shape.
Shape of the orbital
4. Spin Quantum Number ( ms )
 Electron spin  +½ or -½

An orbital can hold 2 electrons that spin
in opposite directions.
Pauli Exclusion Principle

No two electrons in an atom can have the same 4 quantum
numbers.

Each e- has a unique “address”:
1. Principal #
3. Magnetic Quantum Number ( ml )
 Orientation of orbital
 Specifies the exact orbital within each sublevel
 Each orientation can hold 2 electrons max

2. Ang. Mom. # 
energy level (1, 2, 3, 4, 5, 6, or 7) [Period]
sublevel (s,p,d,f)
3. Magnetic #

orbital
4. Spin #

electron
[block on P.T.]
Sketch the shape of an s orbital and a p ortibtal.
1. How does a 2s orbital differ from a 1s orbital?
2. How do a 2px and a 2py orbital differ?