Class Presentation slides for the Third Quarter of Physical Science 50, Spring Semester 2009

1. Light Waves

2. X-rays
3 x 108m/s
 F = c / = 2.19 x 10-10m
= 1.37 x 1018 Hz

3. Radio Waves
Live 105:
105.3 MHz
3 x 108m/s
= c / f = 105.3 x 106 Hz
= 2.85 m

4. Red Light
= 728 nm

= 7.28 x 10-7m
3 x 108m/s
7.28 x 10-7m
f = c/ =
4.12 x 1014 Hz
=

5. Light Energy
Planck’s Law:

E=hf
High frequency -> High energy

6. Properties of Light
Reflection:

Specular &

diffuse

7. Refraction
“Bending” of light rays

With a change in media

8. Light rays and vision

9. Myopia (Nearsightedness)

10. Lens Correction

11. Hyperopia (Farsightedness)

12. Lens Correction

13. Refracting Telescope

14. Refraction

15. Index of Refraction
c
n= v


16. Refraction due to Temperature
“mirages”


17. Refraction via (temperature)
n (air 0ºC) = 1.0029

n (air 30ºC) = 1.0026

Light travels faster in warm air


18. Refractive Index values
Material Refractive Index
Air 1.0003
Water 1.33
Glycerin 1.47
Oil 1.515
Glass 1.52
Zircon 1.92
Diamond 2.42

19. Laser
Single frequency

Focused

Single direction


20. Incandescent Light Bulb
Filament heated to glow

All visible light

frequencies
All directions


21. Wave Vs. Particle?
Young’s experiment


22. Photoelectric Effect
Quanta

E =hxf

High frequency photons

have more energy

23. Electron Ejection

24. Bohr model for Hydrogen
Niels Bohr

What about more complex atoms?


25. Atomic Theory
Leucippus & Democritus

4th century BC
“indivisible”

eternal, moving

26. Elements

27. Aristotle
 Continuous matter
 Natural motion

28. Age of Experimentation
Lavoisier

(1743 - 1794)
Conservation

of matter

29. Lavoisier
“TraiteElementaire

de Chimie”
HgO --> Hg + oxygène


30. Dalton
 Elements made of atoms
 All atoms of one element are the
same but different than
those of other elements
 Atoms of different elements
can form different combinations
with different properties

31. Compounds
Water Hydrogen Peroxide
H 2O H 2O 2

32. Compounds
Nitrous oxide Nitrogen Dioxide
N 2O NO2

33. Dalton
Atomic masses


34. Benjamin Franklin
Like charges - Repel

Unlike charges - Attract


35. Michael Faraday
Ions = Charged atoms


36. +/- Charged Particles
J.J. Thomson (1897) Cathode rays

37. The Size of an Electron
Millikan (1911)

me = 9.11 x 10-31 kg
1 H atom
= 1840

38. Positive Particle?
Rutherford (1907)

particle = He+ nucleus

39. Neutrons
Chadwick (1932)

Neutron = neutral

= “spacer”

40. Atomic Structure
Plum pudding planetary


41. Subatomic particles
Quarks


42. Atomic Number
 Atomic Number =
# of protons
 Atomic Mass =
protons + neutrons

43. Isotopes

44. Unstable Isotopes

45. Radioactivity
Henri Becquerel


46. Radioactivity
Marie Sklodowska

and Pierre Curie

47. Alpha Decay

48. Beta Decay

49. Gamma Radiation

50. Radiation Safety
Paper

Al foil

Lead


51. Artificial Elements

52. Rate of Decay: Half Life

53. Isotope Half Lives
Isotope Half Life
4.5 x 109 years
U - 238
Pu - 239 24,360 years
C - 14 5730 years
Co - 60 5.3 years
I - 131 8 days
1.63 x 10-4 sec
Po - 214

54. Medical Radioisotopes
 99Tc and 123I

55. Technetium Half life
99Tc half life = 6 hours
If 10 g injected into a patient, how much is
left after 24 hrs?
24 hrs = 4 x 6 hrs = 4 half lives
10 g -> 5 g -> 2.5 g -> 1.25 g -> 0.625 g

56. Radiocarbon Dating
Atomic Clock


57. Radiocarbon Dating

58. Shroud of Turin

59. Ice Man (Ötzi)

60. Nuclear Fission
Otto Hahn &

Lise Meitner

61. Chain Reaction

62. Fission Energy
Control rods

= moderators
usually Boron,
Carbon
Keep reaction

under control

63. Manhattan Project

64. US Fission Reactors

65. Three Mile Island (TMI) 1979

66. Chernobyl 1986

67. Breeder Reactor

68. Fast Breeder Reactions

69. Radioactive Waste

70. Fusion

71. Fusion into Heavier Elements

72. Fission vs. Fusion
High energy higher energy
Radioactive waste no radioactivity
Need fissionable small common
nuclei atoms
Currently used need solar
conditions

73. Cold Fusion (1989)
Fleischman/Pons (Utah)

74. Cold Fusion

75. Cold Fusion (2005)
 Naranjo, Gimzewski & Putterman
 Using a strong Electric Field

76. Tokamak reactor

77. Chemical Reactions
Proton Transfer Electron Transfer
H+ e-
acids/bases reduction/oxidation

78. Proton Transfer
 Acid: Sour taste, corrosive
Releases H+
 Base (alkaline): bitter, corrosive
Accepts H+

79. Identifying Acids, Bases
2 HBr + CaO --> H2O + CaBr2

80. Identifying Acids, Bases
2 HBr + CaO --> H2O + CaBr2
ACID BASE
All proton transfer reactions must have
BOTH an acid and a base

81. Amphoteric Compounds
H2O + HCl --> H3O+ + Cl–
H2O + NH3 --> OH– + NH4+

82. pH
“pouvoir hydrogène”
pH = – log10 [H+]
Acid: excess H+,low pH
Base:H+ deficit, high pH

83. pH scale
Low pH
acid
pH = 7
neutral
High pH
basic

84. “pH Balanced”

85. Buffers
Combination of acid/

base form designed
to keep pH at set
level

86. Antacids

87. Excess Stomach Acid
Overindulgence

Skipping meals

Stress


88. Antacid = Mild Base
Sodium Bicarbonate

NaHCO3
NaHCO3 + HCl --->
H2CO3 --->
carbonic acid
CO2 + H2O

89. Sodium - Free?
Hypertension


90. Alka Seltzer
NaHCO3 + aspirin + citric acid


91. Calcium Carbonate
Twice the acid relief!

CaCO3 + 2 HCl --->
H2CO3 --->
CO2 + H2O

92. Milk of Magnesia
 No gas
Mg(OH) 2 + 2 HCl ->
2 H2O + MgCl2
 High dose = laxative

93. Acid Rain
Rainfall with

ph < 5.5
Normal rain

is mildly acidic
due to H2CO3 (carbonic acid)

94. Locations

95. Causes
Impurities in fossil fuels: N, S (+ O2)
NOx, SOx

96. Effects of Acid Rain
Limestone, marble erosion


97. Effects of Acid Rain

98. Chemical Reactions
Proton Transfer Electron Transfer
H+ e-
acids/bases reduction/oxidation

99. Electron Transfer
 Oxidation
electron loss
 Reduction
electron gain

100. Electron Transfer
 Oxidation
electron loss
2 Ag --> 2 Ag+ + 2 e-
 Reduction
electron gain
silver tarnishing
S + 2 e- --> S2-

101. Electron Transfer
 Oxidation
Oxygen gain C + O2 --> CO2
NH4+ --> N2 (rocket fuel)
Hydrogen loss
 Reduction
ClO4- --> Cl2 (rocket fuel)
Oxygen loss
Hydrogen gain C18H34O2 --> C18H36O2
unsat Oleic acid sat Stearic acid

102. Safety Matches
Red
3 S + 2 KClO3 -> 2 KCl + 3 SO2
ox

103. Biological Redox
Alcohol metabolism


104. Alcohol Metabolism
Liver Aldehyde
alcohol oxidase
dehydrogenase
Acetic
acid

105. Hangover
Nausea

Headache

Sensitivity to

light, sound

106. Batteries
Daniell cell:
Cu and Zn

107. Battery Operation
Anode: oxidation Zn -> Zn2+ + e-
Cathode: where reduction occurs
MnO2 + e- Mn2O3

108. Alkaline Batteries
Anode: Manganese
Cathode: Zinc

109. Rechargeable Batteries
Ni-cad

Cd -> Cd2+ + e-
NiO2 + e- ->NiO

110. NiMH batteries
Higher capacity

Longer lifetime

NiOOH -> Ni(OH)2 (Ni+/Ni2+ oxidation)

M+H- -> M (reduction)

111. Lead-Acid Batteries
Pb + SO42- -> PbSO4 + 2e-
PbO2 + 4 H+ + SO42- + 2e- -> PbSO4 + H2O

112. Corrosion
Fe -> Fe2+ oxidation
O2 -> OH- reduction

113. Statue of Liberty
Gift from
France 1876

114. Renovation (1986)

115. Capturing Light
Louis Daguerre


116. Exposure
Silver salts: AgBr or AgI

Light + 2 Ag+ X- 2 Ag+* + X2

117. Development
Ag+* + C6H6O2 Ag + HBr + C6H4O2
Use Acid to Stop this process

118. Fixing
Removes excess insoluble Silver:

Ag+ + S2O32- Ag(S2O3)-

HYPO

119. Color Photography
Light + Ag+ + Dye -> Ag+* + Dye*


120. Instant Photography
Polaroids
