1. Unit 8 Notes 1 Molecules Law of Definite and Multiple Proportions
Law of Conservation of Mass
Dalton’s Atomic Theory
Calculating Average Atomic Mass

2. Laws of Proportions What is the proportion for? H2O H2O2 N2O3 2:1 N2O5
Definite Proportions
2:1
1:1
2:3
Multiple Proportions
2:5
2:1
1:2

3. Law of Conservation of Mass
2H2(g) + 1O2(g)→2H2O(l)
H = 2 x = 4.0
O = 1 x 32.0 = 32.0
H = 2 x = 4.0
O = 2 x 16.0 = 32.0 + +
36.0
36.0
3H2(g) + 1N2(g)→2NH3(l)
N = 2 x 14.0 = 28.0
H = 2 x = 6.0
N = 1 x 28.0 = 28.0
H = 3 x = 6.0 + +
34.0
34.0
2C2H6(g)+ 7O2(g)→ 4CO2(g) + 6H2O(l)
C = 2 x 24.0 =
H = 2 x =
O = 7 x 32.0 = 244.0
C = 4 x 12.0 = 48. 0
H = 6 x = 12.0
O = (4 x 32.0) + (6 x16.0) = 244.0

4. Three laws that support the existence of atoms
1. Law of Definite Proportions
2. E=MC2
3. Law of Multiple Proportions 4

5. Principles of Dalton's Atomic Theory
1. All matter is made of indivisible and indestructible atoms.
2. All atoms of a certain element are identical in mass and properties.
3. Compounds can be formed by using two or more different kinds of atoms.
4. A chemical reaction is a rearrangement of atoms. 5

6. Carbons Mass in amu and gram units
1 amu=1/12 C-12
1 C-12 mass = amu
1 amu = X10-24 grams.
grams/Mole! 6

7. Calculating Average Atomic Mass
E amu % product
C-12 x
98.90 =
C-13 x
1.10 =
1187
1187
98.90 % %
1201 %
1201
÷100.00
= 12.01amu
4 sd
5 sd
4 sd 7

8. Unit 8 Notes 2 The Nucleus Review of Average Atomic Mass Cathode Ray
Varies Experiments
Nuclear Reactions
Atomic Particles 8

9. Calculating Average Atomic Mass
E amu % product
79Br x
50.697 = =
81Br x
49.317
4000.9 % %
7991.4 %
7991.4 ÷
= amu
5 sd
6 sd
5 sd
= amu

10. Cathode Ray Electrons(e-1) go toward the anode - + e-1→ e-1→ e-1→ e-1→
Examples: TV and Computer Monitor

11. Cathode Ray Devices 11

12. Van de Graff
←Leyden Jar
Van de Graff generator➔

13. Millikan's oil-drop experiment
Charge of e-1 is equal to x Coulombs.
Oil drops→
← perfume sprayer
hole→
← (+) plate . -2 . -1
X-ray→ .
battery→
← (-) plate 13

14. Rutherford's experiments
Alpha particle→
Lead
Radium→
α+2
8000 α →
Microscope→
7999 α pass through
42He+2
Gold Foil↑
10,000 atoms thick
α+2
Characteristics of atoms
mostly empty space
+79
Small(1/10,000),
dense, and
heavy
positive charge core 14

15. Atoms and their electrons, protons, and neutrons
Proton(P+1) + Neutrons(n0)= Mass #(Z)
Isotope Name =
Element – Mass # A Z
Element
P+1 n0
Symbol
Name 1 1 1
Hydrogen 1 H
Hydrogen -1 1 1 2
Hydrogen 1 1 H 2
Hydrogen -2 1 1 3
Hydrogen 1 2 H 3
Hydrogen -3 1 8 16
Oxygen 8 8 O 16
Oxygen
-16 8 26 57
Iron 26 31 Fe 57
Iron
-57 26

16. Nuclear Reactions U + n → Xe + Sr + n n+ Li → H + He + n U → Th + He β
A reaction, as in fission, fusion, or radioactive decay, that alters the energy, composition, or structure of an atomic nucleus.
Fission:
235
U + 1
n →
135
Xe +
100 Sr
+ n 1 92 54 38
Fusion: 1 n+ 7
Li → 3 H
+ He + 4 1 n 3 1 2
Decay:
238
U →
234
Th + 4 He
Alpha Decay 92 90 2 β
234
Th →
234
Pa +
Beta Decay(e-1) 90 91 -1

18. Atomic Particles In an atom, the nucleus is about 10-15 in size
Symbol
Charge
Mass (g)
Mass (amu)
proton p+ +1
1.673 x 10-24
neutron n0
1.675 x 10-24
electron e- -1
9.109 x 10-28
5.485 x 10-4
In an atom, the nucleus is about in size
A proton is about 1835x more massive than an electron

19. Unit 8 Notes 3 Electron Arrangements for Elements
De Broglie’s Wave Model
Orbital Shapes
State Pauli's exclusion Principle, the aufbau principle, and Hund's rule.
Orbital Filling Diagrams

20. De Broglie’s Wave Model for Electrons
Wave Nature
Different solutions for e-1 actions.
e-1’s act as a particle or a wave.
e-1’s absorb or release Quantum Amount of NRG.
Demo of waves on a string

21. S Orbital
y-axis
z-axis
X-axis

22. P Orbitals Shapes
x-axis
y-axis
z-axis

23. p Orbitals Assembled
y-axis
z-axis
x-axis

24. Quantum Model for The Shell of The Atom

25. Electron Order of Filling
Aufbau Principle - Fill the lowest energy level first
Hund’s Rule - Everything is paired up last
Pauli Exclusion Principle - Spins are always opposite

26. Orbital Filling Diagram
Write the orbital filling diagram for Ne.
How many electrons does Ne have?
Final Answer
Shorthand Answer
10 e-1 ↑ ↑ ↑ ↑ ↑ ↑ 1s 2 2s 2 2p 6 ↑ ↑
[He] 2s 2 2p 6 ↑ ↑ 26

27. Orbital Filling Diagram
Write the orbital filling diagram for Na.
How many electrons does Na have?
Final Answer
Shorthand Answer
11 e-1 ↑ ↑ ↑ ↑ ↑ ↑ ↑ 1s 2 2s 2 2p 6 3s 1 ↑ ↑
[Ne] 3s 1 ↑ ↑ 27

28. Orbital Filling Diagram
Write the orbital filling diagram for Cl.
How many electrons does Cl have?
Final Answer
Shorthand Answer
17 e-1 ↑ ↑ ↑ ↑ ↑ ↑ ↑ 1s 2s 2p 3s 3p 2 2 6 2 5 ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑
[Ne] 3s 3p 2 5 ↑ ↑ 28

29. Unit 8 Notes 4 The Structure of the Atom’s Shell
Review of Atom Models
Electron Dot Configuration
Quantum Numbers
Electromagnetic Spectrum

30. Thompson Model Negative electrons on the positive surface
Atoms mass is positively charged and widely spread.
Electrons don’t move, unless releasing energy.
Ex. Chocolate Chips in Ice Cream

31. Rutherford Model *Mostly Empty Space *Nucleus… Very Small Very Dense+
Positive Charged
Where were the electrons?
What are the electrons doing?

32. Neil Bohr Model e-1 found in the empty space.
He used light to define their actions.
e-1 region +

33. Electromagnetic Spectrum
Visible Light
gamma ray
Short
wave
X-ray UV IR
radar FM TV AM
Short wavelength
Long wavelength
High Energy
Low Energy 33

34. Bohr’s Model of the shell
*Particle Model
*Circular orbits
*Hydrogen only
e-1
Light’s Energy

35. Electron Dot Diagram for Neon
[He] 2s 2 2p 6 ↑ ↑ ↑ ↑ ↑ ↑ ● ● ↑ Ne ↑ ● ● ● ● ● ● ↑ ↑ 35

36. Electron Dot Diagram for Sodium
[Ne] 3s 1 ↑ Na ● ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ 36

37. Electron Dot Diagram for Chlorine3s 2 3p 5 ↑ ↑ ↑ ↑ ↑ ● ● Cl ↑ ↑ ● ● ● ● ↑ ↑ ↑ ● ↑ ↑ ↑ ↑ ↑ ↑ ↑

38. Quantum Numbers Addresses for electrons Four numbers for each address
No two addresses are the same
First number is n =1
, 2
, 3
, 4
, 5
, 6
, 7
(Distance
From the
Second number is l
= 0
, 1
, 2
, 3
Nucleus) s p d f
Third number is ml
= 0
s orbital
= +1, 0, -1
p orbital
= +2, +1, 0, -1, -2
d orbital
= +3, +2, +1, 0, -1, -2 , -3
f orbital
Forth number is ms
= +1/2
or -1/2

39. Quantum Numbers ms = +1/2 or -1/2= n= 3 l= 1 ml = ms = -1/2↑ ↑ ↑
ms = +1/2 or -1/2= n= 3 l= 1
ml =
ms =
-1/2
l = 0(s), 1(p), 2(d), 3(f) =

40. Quantum Numbers ms = +1/2 or -1/2= n= 7 l= ml = ms = +1/2↑ ↑ ↑
ms = +1/2 or -1/2= n= 7 l=
ml =
ms =
+1/2
l = 0(s), 1(p), 2(d), 3(f) =

41. Quantum Numbers ↑ n= 4 l= 3
ml = +2
ms =
-1/2

42. Quantum Number for Last e-1 in In→ → → → → →
What element are we looking for? → → → → → → →
What block is it in?
How many into the block is it?
Where does the final arrow fall?
Quantum #’s for Last e-1 n= 5 l= 1
ml= +1
ms=
+1/2 42

43. Unit 8 Notes 5 Spectroscope
Analyzing Spectrums

44. The Spectroscope Prism slit Bright-line Emission Spectrum Helium Tube
spectrograph

45. Solar Spectrum➔
(92 elements)
hydrogen➔
helium➔
mercury➔
uranium➔

46. Spectrum Example #1 n=6 n=5 n=4 Excited State n=3 n=2 Quantum Amount
Violet
indgo
Blue
Green
Yellow
Orange
Red
n=5
n=4
Excited State
n=3
n=2
Quantum Amount
n=1
Ground State
energy

47. Spectrum Example #2 n=6 n=5 n=4 Excited State n=3 n=2 Quantum Amount
Violet
indgo
Blue
Green
Yellow
Orange
Red
n=5
n=4
Excited State
n=3
n=2
Quantum Amount
n=1
Ground State
energy

48. Spectrum Example #3 n=6 n=5 n=4 Excited State n=3 n=2 Quantum Amount
Violet
indgo
Blue
Green
Yellow
Orange
Red
n=5
n=4
Excited State
n=3
n=2
Quantum Amount
n=1
Ground State
energy