1. The document discusses quantum numbers and their use in describing the electrons in an atom. It defines the four quantum numbers - principal (n), angular momentum (l), magnetic (ml), and spin (ms) - and provides examples of their values for different electron configurations. 2. It then asks the reader to assign quantum numbers to the valence electron of lithium and the tenth electron of neon. 3. The document concludes with multiple choice practice questions related to quantum numbers.

1. Homework # 10
1. Worksheet: Quantum Numbers
2. Assign quantum numbers to the
valence electron of a lithium.
3. Assign quantum numbers for the
tenth electron to fill a neonatom.

2. Aim 10: How can you describe the
quantum mechanical model?

3. Quantum #’s are like an Address.
What do you need to know to find out where
you live?
State City Street House
Principle
Quantum
number
(n)
Angular
Quantum
number
(ℓ)
Magnetic
Quantum
number
(mℓ)
Spin
Quantum
number
(ms)

4. 1. Quantum Numbers
• Modern atomic theory states that any electron
in an atom can be completely describe by four
quantum numbers: n, l, ml ,ms

5. 1st Quantum Number: Principal
Quantum Number (n)
• Refers to the principal energy levels.
n
1
2
3
4

6. 2nd Quantum Number: Azimuthal or
Angular Momentum Quantum
Number (ℓ)

7. • ℓ can be any integer from 0 to n-1
• Sublevel (s,p,d,f)
• Describe the shape of the orbital
Letter s p d f
ℓ 0 1 2 3

8. Example: n = 3
ℓ = 0 ….n-1
ℓ = 0 ….(3-1)
ℓ = 0 to 2
letter s p d f
ℓ 0 1 2 3

9. S,P,D,F
s: Sharp
p: Principal
d: Diffuse
f: Fundamental
The s, p, d, and f stand for "sharp," "principal," "diffuse," and "fundamental,"
respectively, and are so named because they categorize the spectral lines
generated by those types of orbitals: Electron configuration

10. 3rd Quantum Number: Magnetic
Quantum Number (mℓ)
• Designates the specific three
dimensional orientation of the
orbital ℓ.

11. s subshell: spherical
1 S 2 S 3 S

12. p subshell : dumbbell shape
3 orbitals
x y z
x
y
z

13. d subshell

14. Example: ℓ= 2
mℓ = -2, -1, 0, +1, +2

15. S ___
0
d ____ ____ ____ ____ ____
-2 -1 0 1 2
p ___ ____ ____
-1 0 1
f ____ ____ ____ ____ ____ ____ ____
-3 -2 -1 0 1 2 3

16. Value
of l
Sub
shell
Values of
ml
Possible orbitals
0 s 0 S
1 p -1 , 0 , 1 Px,Py,Pz
2 d -2, -1, 0, 1, 2 dxy,dxz,dyz,dx2y2, dz2
3 f -3, -2, -1, 0, 1, 2,3

17. 4th Quantum Number: Spin Quantum
Number (ms )
• the spin of the electron.
• Electrons in the same orbital must have opposite
spins.
The value of ms =
1
2
1
2
or
+ -

18. + ½
- ½
2 S

19. °
x
y
z
+ ½ - ½

20. Possible spins are clockwise or counterclockwise

21. Empty
Half-Filled
Filled MAGNETIC
PARAMAGNETIC
are attracted to a
magnetic field

22. The Pauli exclusion principle
(Wolfgang Pauli, Nobel Prize 1945)
states that:
no two electrons in the same atom can
have identical values for all four of their
quantum numbers. What this means is
that no more than two electrons can occupy
the same orbital, and that two electrons in
the same orbital must have opposite spins.

23. Summary

24. Quantum Numbers
n, l, ml, ms
PEL
SUBLEVEL
SHAPE
ORBITAL
SPIN

25. l = SUBLEVEL (s,p,d,f)
S = 0
P = 1
d = 2
F = 3

26. ml = orbital
s ___
0
p ___ ___ ___
- 1 0 1
d ___ ___ ___ ___ ___
-2 - 1 0 1 2
f ___ ___ ___ ___ ___ ___ ___
-3 -2 - 1 0 1 2 3

27. ms = +1/2, -1/2
• Spin!

30. Oxygen
___ ___ ___ ___ ___
1s2 2 s2 2p4
1
n l ml ms
0 0 1/2
s ___
0
s= 0
P = 1
d =2
f= 3

31. Oxygen
___ ___ ___ ___ ___
1s 2 s 2p
1
n l ml ms
0 0 - 1/2
s= 0
P = 1
d =2
f= 3
s ___
0

32. Oxygen
___ ___ ___ ___ ___
1s 2 s 2p
2
n l ml ms
1 1 1/2
p ___ ___ ___
- 1 0 1
s= 0
P = 1
d =2
f= 3

33. 1. An atom of hydrogen has one electron and is
labeled 1 s1 . What will the quantum be?
n=
ℓ=
mℓ =
ms =

34. 1st: Principal Quantum Number (n)
1 s1
Answer: n= 1

35. 2nd: The angular momentum
quantum Number (ℓ) or subshell
because ℓ is a number from 0 to n-1
1 s1
Answer: ℓ= 0
s= 0
P = 1
d =2
f= 3

36. 3rd: Magnetic Quantum Number (ml)
-l to +l
ml = 0
1 s1 s ___
0

37. 4th: Spin Quantum Number (ms )
1
2
1 s1
Answer: 1
2
+
+

38. The Quantum Numbers are:
1, 0, 0, 1
2

39. 2. Assign quantum numbers to the
valence electrons of a lithium atom
1s22s1
See your periodic table

40. 1st: Principal Quantum Number (n)
1s22s1
Answer: n= 2

41. 2nd: The angular momentum
quantum Number (ℓ) or subshell
Answer: ℓ= 0
1s22s1
s= 0
P = 1
d =2
f= 3

42. 3rd: Magnetic Quantum Number (ml)
-l to +l
ml = 0 , because the value of l is 0
1s22s1 s ___
0

43. 4th: Spin Quantum Number (ms )
1
2
Answer: 1
2
1s22s1 +
+

44. The quantum numbers are:
2,0,0, + 1/2

45. 3. What are the four quantum
numbers that represent an electron in
2 s orbital
n = 2 ℓ= 0
mℓ= 0 ms= +½
-½
s= 0
P = 1
d =2
f= 3

46. 4. What are the four quantum
numbers that represent an electron in
3 p orbital
n = 3 ℓ= 1
mℓ= -1
ms= +½
-½
s= 0
P = 1
d =2
f= 3

47. 5. What are the four quantum
numbers that represent an electron in
5 d orbital
n = 5 ℓ= 2
mℓ= -2 -1 0 +1 +2
ms= +½
-½
s= 0
P = 1
d =2
f= 3

48. 6. What are the four quantum
numbers that represent an electron in
4 f orbital
n = 4 ℓ= 3
mℓ= - 3 -2 -1 0 +1 +2 + 3
ms= +½
-½
s= 0
P = 1
d =2
f= 3

49. 7. Where is an electron with the
quantum numbers:
n = 4
ℓ = 2
mℓ = 0
ms = +½
4 d
s= 0
P = 1
d =2
f= 3

50. 8. Where is an electron with the
quantum numbers:
n = 2
ℓ= 0
mℓ= 0
ms= -½
2 s2

51. s p
d f
sharp principal
diffuse fundamental

52. 9. Assign quantum numbers for the tenth
electron to fill a neon atom.
[He] 2s2 2p6 1s2 2s2 2p6
1 2 2
s s p p p

53. 10. Assign quantum numbers for the tenth
electron to fill a neon atom.
1 2 2
s s p p p
1s2 2s2 2p6
n = 2 L = 1

54. Practice: MCQ Questions
http://www.ualr.edu/rebelford/chem1402/q140
2/X3/c7/7-3/7-3.htm#JUMP_11

55. 1
1) 1
2 )2
3) 3
4) 4

56. 2
1) 0
2) 1
3) 2
4) 3

57. 3
1) 0
2) 1
3) 2
4) 3

58. 4
1) 0
2) 1
3) 2
4) 3

59. 5
1) 1
2) 2
3) 5
4) 7

60. 6
1) Principle
2) Azimuthal
3) Magnetic
4) spin

61. 7
1) Principle
2) Azimuthal
3) Magnetic
4) spin

62. 1) Principle
2) Azimuthal
3) Magnetic
4) spin

63. 9
1) orbitals
2) Wave functions
3) nodes
4) null points

64. 10
1) n
2) l
3) ml
4) ms

65. 11
1) Aufbau Principle
2) Pauli Exclusion Principle
3) Heisenberg Uncertainty Principle
4) Mendeleev’s Priciple

67. n l ml
Number of
orbitals
Orbital
Name
Number of
electrons
1 0 0 1 1s 2
2 0 0 1 2s 2
1 -1, 0, +1 3 2p 6
3 0 0 1 3s 2
1 -1, 0, +1 3 3p 6
2 -2, -1, 0, +1, +2 5 3d 10
4 0 0 1 4s 2
1 -1, 0, +1 3 4p 6
2 -2, -1, 0, +1, +2 5 4d 10
3
-3, -2, -1, 0, +1,
+2, +3
7 4f 14