1. Quantum Theory
(Chapter 4)

2. Quantum Theory Treats electron’s location as wave property
Defined by quantum numbers
Orbitals have different energies
Quantum numbers
Provide information about size, shape, and orientation of atomic orbitals
Define atomic orbitals from general to specific

3. Quantum Mechanical Model
Opposite charges attract, electrons are attracted to the nucleus of an atom
Takes a LOT of energy to keep electrons away from the nucleus.
Electrons are found at differing lengths from the nucleus and can only be present in certain locations
Some ideas are old.

4. Principal Quantum Number (n)
Determines orbital size and electron energy
Same as “n” value/orbital in Bohr model
Positive whole number, NOT 0
Shells – orbitals with same value
n = 1, 2, 3, 4, etc.

5. Orbital Angular Momentum Quantum Number (l)
Defines orbital shape for a particular region of atom
Think of as “subshell”
Energy sublevels—within the main energy level
s = 1 orbital, can hold 2 electrons
p = 3 orbitals, can hold 6 electrons
d = 5 orbitals, can hold 10 electrons
f = 7 orbitals, can hold 14 electrons

6. Orbital Shapes s orbital p orbital
1 possible orbital orientation, spherical shape
n value determines size
Charge cloud found near center, likely electron location
p orbital
3 possible orbital orientations, dumbbell shape
pX, py, pz

7. l
Orbital/Subshell s 1 p 2 d 3 f

8. Energy levels and Sublevels

9. How do you specify orbitals?

12. Magnetic Quantum Number (ml)
Describes orbital orientation within an atom
ml = -l to +l (number of orientations)

13. Ex.1: L = 0
Ml = 0
S shape
Can only be in one orientation

14. Ex. 2: L =1 Ml = -1, 0, 1 p shape 3 possible orientations
How many orbitals in p subshell?

15. Ex. 3: L = 2 ml = -2, -1, 0, 1, 2 d shape/subshell
How many orientations? How many orbitals?

16. Electron Spin Describes the motion of an electron, spinning
As electron moves, magnetic field induced
Electrons with opposite spins, cancel magnetic field of other
Values: +1/2, -1/2

17. What does atomic structure REALLY look like?P

18. Homework
Complete Quantum Worksheet
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