Chapter 07: The Quantum-Mechanical Model of the Atom Flashcards Preview

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Flashcards in Chapter 07: The Quantum-Mechanical Model of the Atom Deck (45)
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31

Quantum numbers (4)

1. Principal quantum number, n

2. Angular momentum quantum number, l

3. Magnetic quantum number, ml

4. Spin quantum number, ms

32

Principal quantum number

n

Indicates the orbital (Bohr's energy level)

*As n gets larger, amount of energy between orbitals gets smaller

33

Equation for energy of a hydrogen electron

En = -RH (1/n2)

RH is Rydberg constant for hydrogen
RH = 2.18 × 10-18 J

34

Angular momentum quantum number

l

Angular momentum = what kind of/angle of orbit

l = 0, 1,... n-1

l = 0 → s
l = 1 → p
l = 2 → d
l = 3 → f

e.g.
n = 2
l = [0, 1]

35

Magnetic quantum number

ml

ml = [-l, l]

e.g.
n = 2
l = [0, 2] → d orbital
ml = [-2, 2] → 5 d orbitals

36

Spin quantum number

ms

Specifies the orientation of the spin of the electron

Value is either:
+1/2 (spins up)
or
-1/2 (spins down)

37

Describing an orbital (3)

1. n, l, ml describes one orbital
2. Orbitals with same n value = same principal energy level (shell)
3. Orbitals with the same values of n & l = same sublevel (subshell)

38

Equation for energy transition in hydrogen

ΔE = Efinal - Einitial

ΔEH atom = -2.18 × 10-18 J (1/n2final - 1/n2initial)

Energy emitted by electron is carried away by the releated photon, thus:

Ephoton = -ΔE

39

Probability density

The probability of finding an electron at a particular point in space

Probability decreases as distance from nucleus increases

40

Radial distribution function

Total probability of finding an electron at a certain distance r from the nucleus

Volume of shell also increases with distance from nucleus

41

Nodes

Where the probability drops to zero, for both probabilities

42

s orbital

l = 0

spherical shape

1 s orbital

43

p orbital

l = 1

shaped like two balloons

-1, 0, 1

3 p orbitals

44

d orbital

l = 2

shaped like four balloons

-2, -1, 0, 1, 2

5 d orbitals

45

f orbital

l = 3

shaped like eight balloons

-3, -2, -1, 0, 1, 2, 3

7 f orbitals