Science, Matter, and Science, Matter, and EnergyEnergy

Chapter 2Chapter 2

An Environmental Lesson from An Environmental Lesson from Easter Island- Tragedy of the Easter Island- Tragedy of the

CommonsCommons Colonized about 2,900 years agoColonized about 2,900 years ago

Soil and tree resources exhaustedSoil and tree resources exhausted

Over 300 statuesOver 300 statues

By 1600 AD, few trees leftBy 1600 AD, few trees left

Islanders trapped and starvedIslanders trapped and starved

War / cannibalism over remaining War / cannibalism over remaining resourcesresources

Dutch arrived 1722Dutch arrived 1722

Key ConceptsKey Concepts

Science is a process for understandingScience is a process for understanding

Matter: Basic forms and resourcesMatter: Basic forms and resources

Energy: Basic forms and resourcesEnergy: Basic forms and resources

Scientific laws governing matter and energyScientific laws governing matter and energy

Physical and chemical propertiesPhysical and chemical properties

Nuclear changes and radioactivityNuclear changes and radioactivity

Science and Critical ThinkingScience and Critical Thinking What is science?What is science?- - attempt to discover order in nature & make attempt to discover order in nature & make

predictionspredictions

Scientific dataScientific data

Experiments Experiments

Scientific hypothesesScientific hypotheses- - working explanation for observationsworking explanation for observations

Scientific modelsScientific models

Scientific theoriesScientific theories- - repeatedly supported hypothesis- reliable & repeatedly supported hypothesis- reliable & acceptedaccepted

Natural laws- Natural laws- well-tested and accepted patterns in datawell-tested and accepted patterns in data

Scientific ProcessScientific Process

Science vs. Junk ScienceScience vs. Junk Science Scientific method(s)Scientific method(s) - - single and multivariable analysissingle and multivariable analysis

Scientific results-Scientific results- “ “absolute truth?”absolute truth?”

Frontier science-Frontier science- not confirmednot confirmed

Sound science (consensus science)Sound science (consensus science) - - widely widely accepted, peer reviewaccepted, peer review

Junk scienceJunk science - - Untested ideas presented as sound science- can Untested ideas presented as sound science- can be used to mislead for political gainbe used to mislead for political gain

Matter and its TypesMatter and its Types What is matter? = What is matter? = anything with mass. 2 forms:anything with mass. 2 forms:

1. 1. Elements = Elements = building blocks of matterbuilding blocks of matter

2. 2. Compounds = Compounds = 2 or more elements bonded chemically2 or more elements bonded chemically

Chemical bondsChemical bonds

Atoms = Atoms = smallest unit of mattersmallest unit of matter

Ions = Ions = electrically charged atomelectrically charged atom

Chemical formulasChemical formulas

Organic vs. inorganic compounds Organic vs. inorganic compounds

Levels of Levels of Organization Organization

of Matterof Matter

Organic Compounds- Organic Compounds- contain at least 2 or more C atoms combined with each other & contain at least 2 or more C atoms combined with each other &

atoms of 1 or more other elements.atoms of 1 or more other elements. Hydrocarbons: Hydrocarbons: ex. ex. CHCH44

Chlorinated hydrocarbons: Chlorinated hydrocarbons: ex. DDTex. DDT

Simple carbohydrates (simple sugars) Simple carbohydrates (simple sugars) ex.ex. CC66HH1212OO66

Polymers = Polymers = monomers linked together; 3 typesmonomers linked together; 3 types

1. Complex carbohydrates1. Complex carbohydrates

2. Proteins2. Proteins

3. Nucleic acids (DNA and RNA)3. Nucleic acids (DNA and RNA)

AtomsAtoms Subatomic particlesSubatomic particles

• ProtonsProtons• NeutronsNeutrons• ElectronsElectrons

Atomic number Atomic number = # of protons= # of protons

Mass number Mass number = # neutrons + # protons= # neutrons + # protons

Isotopes Isotopes = elements w/ same atomic number, but = elements w/ same atomic number, but different mass number (different # neutrons)different mass number (different # neutrons)

Subatomic particles interaction

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Atomic number, mass number interaction

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Matter QualityMatter Quality High-quality matter- High-quality matter- concentrated, found near concentrated, found near

earth’s surface, usefulearth’s surface, useful

Low-quality matterLow-quality matter - dilute, not easily - dilute, not easily accessible, not usefulaccessible, not useful

Material efficiency (resource productivity)Material efficiency (resource productivity) = total amount of material needed to produce each = total amount of material needed to produce each unit of good or service - Area for improvementunit of good or service - Area for improvement

Changes in MatterChanges in Matter PhysicalPhysical - - chemical chemical

composition not changedcomposition not changed

Chemical - Chemical - chemical chemical composition changedcomposition changed

In text on page 32

Chemical Reaction of Burning Carbon

Law of Conservation of MatterLaw of Conservation of Matter

Matter is not destroyedMatter is not destroyed

Matter only changes formMatter only changes form

There is no “throwing away”There is no “throwing away”

Matter and PollutionMatter and Pollution Harm Caused by Pollution Dependent on 3 factorsHarm Caused by Pollution Dependent on 3 factors::

1. Chemical nature of pollutants1. Chemical nature of pollutants2. Concentration2. Concentration3. 3. PersistencePersistence = length of time pollutant stays in air, water or body= length of time pollutant stays in air, water or body

DegradableDegradable (nonpersistent) (nonpersistent) pollutantspollutants - - broken down by natural broken down by natural processesprocesses

Biodegradable pollutantsBiodegradable pollutants - - broken down by decomposers (sewage)broken down by decomposers (sewage)

Slowly degradableSlowly degradable (persistent) pollutants - (persistent) pollutants - take decades or take decades or longer to degrade (plastics, DDT)longer to degrade (plastics, DDT)

Non-degradable pollutantsNon-degradable pollutants - - not broken down by natural processes not broken down by natural processes (Pb, Hg, As)(Pb, Hg, As)

Nuclear ChangeNuclear Change Natural radioactive decay Natural radioactive decay - - unstable isotopes unstable isotopes

emit matter and/or high-energy radiationemit matter and/or high-energy radiation

Radioactive isotopes (radioisotopes)Radioactive isotopes (radioisotopes)

Half-life Half-life (about 10 half lives for radioactive waste to be safe)(about 10 half lives for radioactive waste to be safe)

Radiation (alpha, beta, and gamma)Radiation (alpha, beta, and gamma) - - exposure can alter DNA, damage tissue, cause burns, exposure can alter DNA, damage tissue, cause burns, miscarriages, cataracts, and cancermiscarriages, cataracts, and cancer

Nuclear ReactionsNuclear Reactions

Fig. 2-6, p. 33

Fig. 2-6, p. 33

Fission Fusion

Fig. 2-6, p. 33

Stepped Art

Neutron

Uranium-235

Fissionfragment

Fissionfragment

Energyn

n

n

Energy

Energy

n

n

n

Energy

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Uranium-235

Nuclear Nuclear (Fission) (Fission)

Chain Chain ReactionReaction

Fig. 2-6, p. 33

Nuclear (Fusion) Chain Nuclear (Fusion) Chain ReactionReaction

FuelReaction

conditions Products

Energy

100million °C

Neutron

+

+

+

NeutronProton

Hydrogen-2(deuterium nucleus)

Helium-4 nucleus

Hydrogen-3(tritium nucleus)

Nuclear FissionNuclear Fission

Critical Mass Critical Mass = amount of fissionable nuclei = amount of fissionable nuclei needed to sustain a chain reaction needed to sustain a chain reaction

Chain Reaction Chain Reaction = releases an enormous = releases an enormous amount of energyamount of energy

Nuclear FusionNuclear Fusion

Uncontrolled Uncontrolled - thermonuclear weapons- thermonuclear weapons

Controlled Controlled - produce heat for electricity - produce heat for electricity still experimentalstill experimental

EnergyEnergy

Definition: The ability to do “work” Definition: The ability to do “work” and transfer heat and transfer heat

Types: kinetic and potentialTypes: kinetic and potential

Electromagnetic radiation: Electromagnetic radiation: wavelength and energy contentwavelength and energy content

Martian doing mechanical work

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Sun

High energy, shortwavelength

Wavelength in meters(not to scale)

Low energy, longwavelength

Ionizing radiation Nonionizing radiation

10-14 10-12 10-8 10-7 10-6 10-5 10-3 10-2 10-1 1

Cosmicrays

Gammarays

X raysNear

ultravioletwaves

Farultraviolet

waves

Nearinfraredwaves

Farinfraredwaves

microwavesTV

wavesRadiowaves

visiblewaves

Electromagnetic SpectrumElectromagnetic Spectrum

All electromagnetic energy travels at 186,000 miles per second

Very high

High

Moderate

Low

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-temperature heat(greater than 2,500°C)for industrial processesand producing electricity torun electrical devices(lights, motors)

Mechanical motion (to movevehicles and other things)High-temperature heat(1,000–2,500°C) forindustrial processes andproducing electricity

Moderate-temperature heat(100–1,000°C) for industrialprocesses, cooking,producing steam,electricity, and hot water

Low-temperature heat(100°C or less) forspace heating

RelativeEnergy Quality

(usefulness)

Source of Energy Energy Tasks

Energy QualityEnergy Quality

First Law of ThermodynamicsFirst Law of Thermodynamics

Energy is not created or destroyed Energy is not created or destroyed

Energy only changes formEnergy only changes form

Can’t get something for nothingCan’t get something for nothing

Energy input = Energy outputEnergy input = Energy output

Total energy remains constant

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Second Law of ThermodynamicsSecond Law of Thermodynamics

In every transformation, some In every transformation, some energy quality is lostenergy quality is lost

You can’t break even in terms of You can’t break even in terms of energy qualityenergy quality

Second Law greatly affects lifeSecond Law greatly affects life

Examples of the Second Law Examples of the Second Law

Cars: only 20-25% gasoline produces Cars: only 20-25% gasoline produces useful energyuseful energy

Ordinary light bulb: 5% energy is useful Ordinary light bulb: 5% energy is useful light, rest is low-quality heatlight, rest is low-quality heat

Living systems: quality energy lost with Living systems: quality energy lost with every conversion every conversion

Solarenergy

Chemical energy(photosynthesis)

Chemicalenergy(food)

Mechanicalenergy

(moving,thinking,

living)

Wasteheat

Wasteheat

Wasteheat

Wasteheat

Fig. 2-8, p. 36

Second Law of Second Law of ThermodynamicsThermodynamics

Energy flow animation

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Matter and Energy Change: Laws Matter and Energy Change: Laws and Sustainability and Sustainability

Unsustainable high-throughput (high-Unsustainable high-throughput (high-waste) economieswaste) economies

Matter-recycling-and-reuse economyMatter-recycling-and-reuse economy

Sustainable low-throughput (low-waste) Sustainable low-throughput (low-waste) economies economies Lessons from Nature: Low-Lessons from Nature: Low-throughput Economythroughput Economy

Economic types interaction

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