1. Quantum Numbers Activity

2. Warm-Up Write the electron configuration for Uranium
Now, write the abbreviated electron configuration for Europium

3. Electron Configurations
The distribution of electrons into the various energy shells and subshells in an atom in its ground state is called its electron configuration.
Each energy shell and subshell has a maximum number of electrons it can hold.
s = 2, p = 6, d = 10, f = 14.
Based on the number of orbitals in the subshell.
We place electrons in the energy shells and subshells in order of energy, from low energy up.
Aufbau principle.
Tro's "Introductory Chemistry", Chapter 9

4. Quantum Numbers Like giving each electron its own address
Quantum numbers tell us properties of the atomic orbitals, and electrons, in an atom
Like giving each electron its own address
We understand this idea from electron configurations
An orbital is a 3-D region of an atom where there is a high probability of finding electrons (NOT an actual ring & NOT like the planetary orbitals)

5. Principal Quantum Number Angular Momentum Quantum Number
Magnetic Quantum Number
Spin Quantum Number

6. Textbook
You will need a textbook to look up information about the quantum numbers.

7. Know for each Quantum # Definition Symbol The allowed values
An example
A visual representation of the quantum number

8. Review Quantum Numbers as a Class
Discussion of the 4 types of quantum numbers and there properties

9. Quantum Number Review Notes

10. Quantum Numbers
Used to describe various properties of the orbitals in an electron configuration
Each electron is assigned a set of four quantum numbers which, in order, are n, l, ml , and ms
Like giving each electron its own address

11. Principle quantum number
Definition: indicates the main energy level occupied by the electron
Symbol: n
Values: (written as integers) 1,2,3,4,5,6,7

12. Angular Momentum Quantum Numbers
Definition: indicates the shape of the orbital
Symbol: l
Values:
0 = s
1 = p
2 = d
3 = f
For a specific energy level, the number of orbital shapes available is equal to n -1

13. Magnetic Quantum Numbers
Definition: represents the orientation of an orbital around the nucleus
Symbol: ml
Values: for a p-orbital -1, 0 , 1

14. Spin Quantum Numbers
Definition: represents the spin states of electrons in an orbital
Symbol: ms
Values: +1/2, - ½

16. Can an e- be described by the following set of quantum numbers?
n=2, l=1, ml= -1
All quantum numbers are allowed values

17. 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.

18. 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.

19. 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

20. Replace the ? Mark with an appropriate quantum number.
n=3, l=1, ml=?
n=4, l=?, ml=-2
n=?, l=3, ml=?

21. 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

22. 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

23. Hydrogen’s electron Write electron configuration Draw orbital diagram
ml= 0
ms= +1/2

24. Helium’s second electron
Write electron configuration
Draw orbital diagram
n= 1
l= 0
ml= 0
ms= -1/2

25. Lithium’s third electron
Write electron configuration
Draw orbital diagram
n= 2
l= 0
ml= 0
ms= +1/2

26. Flourine’s 6th electron
Write electron configuration
Draw orbital diagram
n= 2
l= 1
ml= 0
ms= +1/2