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