1. Quantum Model of the Atom
Electrons in Atoms

2. Bohr Model
Auf Bau – Electrons are placed in the lowest energetically available subshell.

3. Auf bau

4. Electron Configuration

6. What is the maximum number of electrons that can occupy the f orbital?
D. 22

7. A neutral atom has electron configuration 1s22s22p63s23p2
A neutral atom has electron configuration 1s22s22p63s23p2. What element is this?
A. carbon
B. nitrogen
C. silicon
D. germanium

8. A neutral atom has an electron configuration of 1s22s22p63s1
A neutral atom has an electron configuration of 1s22s22p63s1. What is its atomic number?
A. 5
B. 11
C. 14
D. 20

9. How many electrons completely fill the 3rd energy level?
B. 14
C. 18
D. 32

10. What is the electron configuration for Lithium?
A. 1s3
B. 1s12s2
C. 1s22s1
D. 1s21p1

11. The letter designations for the first four orbital quantum numbers with the number of electrons per orbital at each sublevel are:
s:2, p:8, d: 18, f: 32
s:1, p:3, d: 5, f: 7
s:2, p:6, d: 10, f: 14
s:1, d:6, p:10, f: 14

12. D. none of the given answers
A neutral atom has an electron configuration of 1s22s22p6. what is the ground state configuration of an element that possesses one more electron?
A. 1s22s22p63s1
B. 1s22s22p7
C. 1s22s32p6
D. none of the given answers

13. S 16e- 1s2 2s2 2p6 3s2 3p4 S 16e- [Ne] 3s2 3p4 Notation Core Electrons
Longhand Configuration
S 16e-
1s2
2s2
2p6
3s2
3p4
Core Electrons
Valence Electrons
Shorthand Configuration
S 16e- [Ne] 3s2 3p4

14. Stability Full energy level Full sublevel (s, p, d, f)
Half-full sublevel

15. Stability Electron Configuration Exceptions Copper
EXPECT: [Ar] 4s2 3d9
ACTUALLY: [Ar] 4s1 3d10
Copper gains stability with a full d-sublevel.

16. Stability Electron Configuration Exceptions Chromium
EXPECT: [Ar] 4s2 3d4
ACTUALLY: [Ar] 4s1 3d5
Chromium gains stability with a half-full d-sublevel.

17. Stability 1+ 2+ 3+ NA 3- 2- 1- Ion Formation
Atoms gain or lose electrons to become more stable.
Isoelectronic with the Noble Gases. 1+ 2+ 3+ NA 3- 2- 1-

18. O2- 10e- [He] 2s2 2p6 Stability Ion Electron Configuration
Write the e- config for the closest Noble Gas
EX: Oxygen ion  O2-  Ne
O e [He] 2s2 2p6

19. The electron configuration of CL- is :
a. [Ne] 2s22p6
b. [Ne] 3s23p5
c. [Ne] 2s23p6
d. [Ne] 3s23p6

20. The electron configuration of sILVER is :
a. [Kr] 5s25d9
b. [Kr] 5s24d10
c. [Kr] 5s14d10
d. [Kr] 5s24d9

21. The electron configuration of the ion that Potassium forms is:
a. [Ne] 3s23p6
b. [Ar] 4s2
c. [Ar] 4s1
d. [Ar] 4s24p6

22. The electron configuration of the ion formed when te gains stability is:
a. [Kr] 5s24d105p4
b. [Xe] 5s24d105p6
c. [Kr] 5s25d105p6
d. [Kr] 5s24d105p6

23. Orbits vs. orbitals

24. Radial Distribution Curve
Quantum Mechanics
Orbital (“electron cloud”)
Region in space where there is 90% probability of finding an e-
Orbital
Radial Distribution Curve

25. Heisenberg Uncertainty Principle
Impossible to know both the velocity and position of an electron at the same time

26. S and p orbitals

27. Schrodingher’s cloud models

28. D orbitals

29. If the accuracy in measuring the position of a particle increases, the accuracy in measuring its velocity will:
A. increase
B. decrease
C. remain the same
D. be uncertain

30. The reason the position of a particle cannot be specified with infinite precision is the:
A. exclusion principle.
B. uncertainty principle.
C. photoelectric effect.
D. principle of relativity.

31. Quantum Numbers Four Quantum Numbers:
Specify the “address” of each electron in an atom
UPPER LEVEL

32. Quantum Numbers 1. Principal Quantum Number ( n ) Main Energy level
Size of the orbital

33. f d s p Quantum Numbers 2. Angular Momentum Quantum # ( l )
Energy sublevel
Shape of the orbital f d s p

34. Quantum Numbers 3. Magnetic Quantum Number ( ml )
Orientation of orbital (x,y,z)
Specifies the exact orbital within each sublevel

35. Quantum Numbers px py pz

36. A spherical electron cloud surrounding an atomic nucleus would best represent:
A. an s orbital
B. a px orbital
C. a px and py orbital
D. a d orbital

37. Which orbitals are dumbbell shaped along the x, y and z axis?
A. s
B. p
C. d
D. f

38. 2s 2px 2py 2pz Quantum Numbers
Orbitals combine to form a spherical shape. 2s
2pz
2py
2px

39. Quantum Numbers n = # of sublevels per level
n2 = # of orbitals per level
Sublevel sets: 1 s, 3 p, 5 d, 7 f

40. Quantum Numbers 4. Spin Quantum Number ( ms ) Electron spin  +½ or -½
An orbital can hold 2 electrons that spin in opposite directions.

41. How many quantum numbers are used to describe the energy state of an atom?

42. Quantum Numbers Pauli Exclusion Principle 1. Principal # 
No two electrons in an atom can have the same 4 quantum numbers.
Each e- has a unique “address”:
1. Principal # 
2. Ang. Mom. # 
3. Magnetic # 
4. Spin # 
energy level
sublevel (s,p,d,f)
Orbital (X,Y,Z)
Electron (+1/2, -1/2)

43. The quantum number that indicates the position of an orbital about the three axes in space is:
A. principal
B. angular momentum
C. magnetic
D. spin

44. How many different orbital shapes can an f sublevel have?

45. The spin quantum number indicates that maximum capacity for electrons within an orbital is:

46. The principal quantum number, n, determines the ____________ of the orbital
A. Orientation
B. Energy
C. Shape
D. Capacity

47. How many possible electron orientations are there in the 4d orbital?

48. Each orbital can hold TWO electrons with opposite spins.

49. WRONG RIGHT Hund’s Rule
Orbitals of equal energy must each possess one electron before any can possess a second.
“Empty Bus Seat Rule”
WRONG
RIGHT

50. Orbital Diagram
Electron Configuration
1s2 2s p4 1s 2s 2p O
8e-

51. S 16e- 1s2 2s2 2p6 3s2 3p4 Dot structure Core Electrons
Longhand Configuration
S 16e-
1s2
2s2
2p6
3s2
3p4
Core Electrons
Valence Electrons

52. Dot structure Cl P

53. Feeling overwhelmed?
Read Chapter 10