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Slide 1Slide 1
Scientific Method
Do experimentsand collect data
Formulate hypothesisto explain data
Do more experimentsto test hypothesis
Revise hypothesisif necessary
© 2004 Brooks/Cole – Thomson Learning
OBSERVE
Ask a question
Experimental Design
Control Groups
Experimental Groups
Compare and Analyze
Slide 2Slide 2
Interpret data
Well-tested andaccepted
hypothesesbecome
scientific theories
EXTREMELY well-tested and
accepted patterns
In data becomescientific laws
Slide 3Slide 3
Chemistry• Atoms• Isotopes• Electron configuration
– Valence electons
– periodic
• Molecules– Diatomic
– More
• Bonding types
Slide 4Slide 4
Click to view animation.
Subatomic particles interaction.
Animation
Slide 5Slide 5
Animation
Click to view animation.
Atomic number, mass number interaction.
Slide 6Slide 6
Hydrogen (H)
0 n1 p
1e1 n1 p
2 n1 p
1e 1e
Mass number = 0 + 1 = 1Hydrogen-1(99.98%)
Mass number = 1 + 1 = 2Hydrogen-2or deuterium(0.015%)
Mass number = 2 + 1 = 3Hydrogen-3or tritium (T)(trace)
Uranium (U)
143 n92 p
146 n92 p
92e 92e
Mass number = 143 + 92 = 235Uranium-235(0.7%)
Mass number = 146 + 92 = 238Uranium-238(99.3%) Figure 3-5
Page 52
© 2004 Brooks/Cole – Thomson Learning
Slide 7Slide 7
Click to view animation.
Positron emission tomography (PET) animation.
Animation
Slide 8Slide 8
Click to view animation.
Ionic bonding animation.
AnimationAnimation
Slide 9Slide 9
Reactant(s)
carbon + oxygen
C + O2CO2 + energy
carbon dioxide + energy
+ energy
Product(s)
black solid colorless gas colorless gas
C
O
OO OC
In-text figurePage 56
Slide 10Slide 10
High Quality
Solid
Salt
Coal
Gasoline
Aluminum can
Low Quality
Gas
Solution of salt in water
Coal-fired powerplant emissions
Automobile emissions
Aluminum ore
Figure 3-6Page 53
© 2004 Brooks/Cole – Thomson Learning
Slide 11Slide 11
What are isotopes?
p pn
pnn
Protium Deuterium Tritium
These atoms are isotopes of hydrogen.
They all have one proton and one
electron,
but different numbers of neutrons.
Slide 12Slide 12
What is radioactivity?
pnn
pnp
An unstable nucleus, like tritium will eject
an energetic particle and transform
into an atom of helium-3 (3He )
3H 3He
Slide 13Slide 13
While tritium is radioactive, the energy of the beta particle is very low.
Tritium is the only radioactive isotope that you can buy in large quantities at the local mall. The tritium present in the entire Livermore Valley groundwater basin equals that found in 30 ‘tritium dial’ watches
Slide 14Slide 14
What is a half-life ?
The half-life is a measure of the rate of decay
In one half-life, half of the atoms decay
1000Tri
tiu
m A
tom
s
750
500
250
00 12 24
Time (years)
Slide 15Slide 15
For every tritium decay, an atom of 3He is produced
0
250
500
750
1000
0 12 24
Time (years)
Tri
tiu
m a
tom
s
0
250
500
750
1000
He
lium
-3 a
tom
s
Slide 16Slide 16
The 3He from 3H decay starts to accumulate once the water has
become groundwater
Age (years) = 18 x ln( 1 + 3He / 3H )
0 years 12 years 24 years
Slide 17Slide 17
Fission fragment
Fission fragment
Energy
n n
n
n
Uranium-235nucleus
Unstablenucleus
Figure 3-11Page 58
Slide 18Slide 18
n
U23592
9236 Kr
Ba14156
n
n
n
9236 Kr
U23592
U23592
Ba14156
9236
Kr
Ba14156
9236
Kr
Ba14156
n
n
n
n
n
n
n
n
U23592
U23592
U23592
U23592
n
Figure 3-12Page 58
Slide 19Slide 19
Fuel Reaction Conditions Products
D-T Fusion
Hydrogen-2 ordeuterium nucleus
Hydrogen-3 ortritium nucleus
Hydrogen-2 ordeuterium nucleus
Hydrogen-2 ordeuterium nucleus
D-D Fusion
+
+
+
+
Neutron
Energy
+ +
Helium-4nucleus
+ +
Helium-3nucleus
Energy
Neutron
++
+ +
100 million ˚C
1 billion ˚CNeutron
Proton+Figure 3-13
Page 59
© 2004 B
roo
ks/Co
le – Th
om
son
Learn
ing
Slide 20Slide 20
Animation
Click to view animation.
Half-life interaction.
Slide 21Slide 21
Energy
Slide 22Slide 22
Types of Energy
• Potential– Stored chemical– Physical position
• Kinetic– Motion– Temperature / Heat
Slide 23Slide 23
Metabolic Use of Energy
• Homeostasis
• Feedback Loops
• Heat Production
Slide 24Slide 24
Rate of metabolicchemical reactions
Heat inputfrom sun andmetabolism Heat loss
from aircooling skin
Heat in body
Positive feedback loop
Bloodtemperature inhypothalamus
Excess temperatureperceived by brain
Sweat productionby skin
Negative feedback loop
Figure 3-3Page 50
Slide 25Slide 25
Click to view animation.
Homeostatic control of temperature animation.
Animation
Slide 26Slide 26
Animation
Click to view animation.
Total energy remains constant animation.
Slide 27Slide 27
1st Law of Thermodynamics
Slide 28Slide 28
Animation
Click to view animation.
Example of mechanical work animation.
Slide 29Slide 29
Sun
High energy, shortwavelength
Low energy, longwavelength
Ionizing radiation Nonionizing radiation
Cosmicrays
Gammarays
X rays Farultraviolet
waves
Nearultraviolet
waves
Visiblewaves
Nearinfraredwaves
Farinfraredwaves
Microwaves TVwaves
Radiowaves
Wavelengthin meters(not to scale)
10-14 10-12 10-8 10-7 10-6 10-5 10-3 10-2 10-1 1
Figure 3-7Page 54
Slide 30Slide 30
Figure 3-8Page 54
Ene
rgy
emitt
ed f
rom
sun
(K
cal/c
m2/m
in)
0
5
10
15
0.25 1 2 2.5 3
Wavelength (micrometers)
Slide 31Slide 31
Figure 3-9Page 55
Convection Conduction Radiation
Heat from a stove burner causes atoms or molecules in the pan’sbottom to vibrate faster. The vibrating atoms or molecules then collide withnearby atoms or molecules, causingthem to vibrate faster. Eventually, molecules or atoms in the pan’shandle are vibrating so fast itbecomes too hot to touch.
As the water boils, heat from the hot stove burner and pan radiate into thesurrounding air, even though airconducts very little heat.
Heating water in the bottom of a pancauses some of the water to vaporizeinto bubbles. Because they are lighter than the surrounding water, they rise. Water then sinks from the top to replace the rising bubbles.This up and down movement (convection) eventually heats all of the water.
Slide 32Slide 32
Figure 3-10Page 55
ElectricityVery–high-temperature heat (greater than 2,500°C)Nuclear fission (uranium)Nuclear fusion (deuterium)Concentrated sunlightHigh-velocity wind
High-temperature heat (1,000–2,500°C)Hydrogen gasNatural gasGasolineCoalFood
Normal sunlightModerate-velocity windHigh-velocity water flowConcentrated geothermal energyModerate-temperature heat (100–1,000°C)Wood and crop wastes
Dispersed geothermal energyLow-temperature heat (100°C or lower)
Very high
High
Moderate
Low
Source of Energy Relative Energy Quality(usefulness)
Energy Tasks
Very–high-temperature heat (greater than 2,500°C) for industrial processes and producing electricity to run electrical devices (lights, motors)
Mechanical motion (to move vehicles and other things)High-temperature heat (1,000–2,500°C) for industrial processes and producing electricity
Moderate-temperature heat (100–1,000°C) for industrial processes, cooking, producing steam, electricity, and hot water
Low-temperature heat(100°C or less) for
space heating
© 2004 B
roo
ks/Co
le – Th
om
son
Learn
ing
Slide 33Slide 33
Solarenergy
Wasteheat
Chemicalenergy
(photosynthesis)
Wasteheat
Wasteheat
Wasteheat
Chemicalenergy(food)
Mechanicalenergy(moving,thinking,
living)
Figure 3-14Page 60
Slide 34Slide 34
2nd Law of Thermodynamics
Slide 35Slide 35
Click to view animation.
Animation
Energy flow animation.
Slide 36Slide 36
System Throughputs
Inputs (from environment)
Outputs (into environment
High-quality energy
Matter
Low-quality energy (heat)
Waste and pollution
Unsustainable high-wasteeconomy
Figure 3-15 Page 61
Slide 37Slide 37
Inputs(from environment)
SystemThroughputs
Outputs(into environment)
Energy
Matter
Energyconservation
Waste andpollution
prevention
Sustainablelow-wasteeconomy
Recycleand
reuse
Pollutioncontrol
Wasteand
pollution
Low-quality energy(heat)
Figure 3-16 Page 61