QUANTUM NUMBERS

• Quantum numbers - help to describe the probable location of an electron in an atom or ion -

1. (n)

l

l

PRINCIPAL QUANTUM NUMBER ( n)

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n = 1n = 2n = 3n = 4n = 5

Angular Momentum quantum number ( l )

sl=0

pl=1

dl=2

fl=3

Magnetic QUANTUM NUMBER (m l )

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–

–

–

–

P sublevel ( 3 orbitals)

s sublevel ( 1 orbital)

ml = 0

ml = 0 ml = -1 ml = +1

ml = -1 ml = 0ml = -2 ml = +2ml = +1

f sublevel ( 7 orbitals)

ml = -1

ml = -2

ml = -3

ml = +2

ml = +3

ml = +1

ml = 0

Spin QUANTUM NUMBER (m s

• + ½ or – ½ • Each electron in an orbital will spin in the opposite direction - Clockwise

and counterclockwise

EX: Finding an electron’s home:

Address: n= 3 l = 1 ml = 0 ms = + ½

Address: n = 4 l = 2 ml = +1 ms = - ½

Pauli Exclusion Principle

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Orbitals and the Periodic Tables, p, d, and f blocks

http://www.ptable.com/

s

s 3p 3d

s 2p

s 4p 4d 4f

s 5p 5d 5f

s 6p 6d 6f

s 7p 7d 7f

1

2

3

4

5

6

7

Orbital Diagrams

• Graphical representation of the electrons in an atom’s electron cloud

• An arrow represents one electron

• Direction of arrow shows spin and which orbital within a sublevel

• Must follow Hund’s rule and Aufbau’s principle when placing electrons in orbitals

Electron Configurations

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