Quantum Numbers
GT Chemistry 11/6/14
Drill
 What are the four quantum numbers?
 What are their symbols?
 What are their names?
 If n = 2, what are the possible values for l?
 HW: Finish Quantum Numbers WS
 SKIP #12, 15-17
Objectives
 IWBAT
 Write quantum numbers for any electron in an
element.
 NOTE:
 STEM Conclusion due 11/14 (Friday)
 EM Spectrum calculations & Quantum Quiz on
11/10 (Monday)
Spin Quantum Numbers
 Definition: represents the spin
states of electrons in an orbital
 Symbol: ms
 Values: +½ , -½
 Positive – spin up
 Negative – spin down
Can an e- be described by the following set
of quantum numbers?
n=2, l=1, ml= -1
All quantum numbers are allowed values
Can an e- be described by the following set
of quantum numbers?
n=1, l=1, ml= +1
Not possible.
The value of l must be less than the value of n.
Can an e- be described by the following set
of quantum numbers?
n=7, l=3, ml= +3
All the quantum numbers are allowed
values.
Can an e- be described by the following set
of quantum numbers?
n=3, l=1, ml=-3
Not possible.
The value of ml must be in the range
-l to +l
Replace the ? Mark with an
appropriate quantum number.
n=3, l=1, ml=?
n=4, l=?, ml=-2
n=?, l=3, ml=?
Can an e- be described by the following set
of quantum numbers?
n=2, l=1, ml=-2
n=3, l=2, ml=+2
n=4, l=3, ml=+3
n=5, l=2, ml=+3
 No
 Yes
 Yes
 No
Writing Quantum Numbers
 You can identify the quantum numbers for any
electron in an element
 Start by writing out the the electron
configuration and orbital diagram for the
element
 Locate the electron in the orbital diagram that
you are solving the quantum number for
 Determine the 4 quantum numbers
Hydrogen’s electron
 Write electron configuration
 Draw orbital diagram
 n= 1
 l= 0
 ml= 0
 ms= +1/2
Helium’s second electron
 Write electron configuration
 Draw orbital diagram
 n= 1
 l= 0
 ml= 0
 ms= -1/2
Lithium’s third electron
 Write electron configuration
 Draw orbital diagram
 n= 2
 l= 0
 ml= 0
 ms= +1/2
Fluorine’s 6th electron
 Write electron configuration
 Draw orbital diagram
 n= 2
 l= 1
 ml= 0
 ms= +1/2
Exit Ticket
 What are the quantum numbers for the last
electron in Neon?