apes chapter #3 science, system, matter and energy
TRANSCRIPT
APES Chapter #3APES Chapter #3
Science, System, Matter Science, System, Matter and Energy and Energy
Nature of ScienceNature of Science
Science-Science- an organized way an organized way of using evidence to learn of using evidence to learn about the natural worldabout the natural world ObservationsObservations HypothesisHypothesis ExperimentExperiment ResultsResults ConclusionConclusion
Scientific MethodScientific MethodObservations and HypothesisObservations and Hypothesis
1.Observations/Questions1.Observations/Questions What you seeWhat you see Inferences-logical interpretations of Inferences-logical interpretations of
what you see.what you see. Questions then arise…….Questions then arise…….
2.Hypothesis2.Hypothesis-scientific and -scientific and testabletestable explanation for observationsexplanation for observations
““If……then……”If……then……”
Scientific MethodScientific MethodExperimental ProcedureExperimental Procedure
3.Experimental procedure-3.Experimental procedure- test the test the hypothesis hypothesis
Must be Must be controlledcontrolled, , reproduciblereproducible
Testing effects of Testing effects of only one variable only one variable (factor in experiment(factor in experimentthat is subject tothat is subject tochange)change)
Other scientists Other scientists need to be able to need to be able to reproduce and reproduce and prove valid.prove valid.
Scientific MethodScientific MethodExperimental ProcedureExperimental Procedure
Subjects you are testing are split into groups:Subjects you are testing are split into groups: Experimental GroupExperimental Group-given the experimental -given the experimental
factorfactor Control GroupControl Group:-what you’re comparing :-what you’re comparing
experimental group to.experimental group to.
Experimental GroupExperimental GroupFertilizerFertilizer
Control GroupControl GroupNo FertilizerNo Fertilizer
Scientific MethodScientific MethodExperimental ProcedureExperimental Procedure
Testing ONE variable while keeping Testing ONE variable while keeping others the sameothers the same Independent (manipulated) variableIndependent (manipulated) variable- -
factor in experiment that’s purposely factor in experiment that’s purposely changed—????changed—????
Dependent (responding) variableDependent (responding) variable —factor —factor that a scientist observes for responses that a scientist observes for responses (changes) in—????(changes) in—????
Scientific MethodScientific MethodResults and ConclusionResults and Conclusion
4. Results4. Results Record data—tables, graphsRecord data—tables, graphs Qualitative data-Qualitative data- physical traits ( physical traits (qualitqualities) ies)
describeddescribed Quantitative data-Quantitative data- measurements measurements
((quantitquantities) ies) 5.Conclusions5.Conclusions
Hypothesis is either supported or rejected. Hypothesis is either supported or rejected. NEVER “PROVEN!”NEVER “PROVEN!”
Can be partly trueCan be partly true Findings always useful!!!Findings always useful!!!
Scientific MethodScientific MethodHypothesis vs. TheoryHypothesis vs. Theory
Hypothesis-Hypothesis- educated, testable explanation for educated, testable explanation for an observationan observation
TheoryTheory Verified, credible and widely accepted Verified, credible and widely accepted
hypothesishypothesis Make future predictionsMake future predictions
Law-Law- mathematical description of what a theory mathematical description of what a theory explainsexplains
Models and Behavior of SystemsModels and Behavior of SystemsSystemSystem
Scientists determine the behavior of a system by Scientists determine the behavior of a system by developing a model of it in regards to matter and energydeveloping a model of it in regards to matter and energy
Set of components that function and interact in regular, Set of components that function and interact in regular, understandable wayunderstandable way
Inputs(from environment)
Throughputs(rates of flow)
Outputs(to environment)
Human Body(inputs may be stored for
different lengths of time)
Energy
Information
Matter
Heat
Ideas and
actionsWaste
and pollution
Models and Behavior of SystemsModels and Behavior of SystemsFeedback LoopsFeedback Loops
Feedback loops are found in a systemFeedback loops are found in a system Output fed back into system leads to changesOutput fed back into system leads to changes
Positive feedback-Positive feedback- AMPLIFICATION AMPLIFICATION i.e. global warmingi.e. global warming
Negative feedback-Negative feedback- CORRECTIVE CORRECTIVE System changes in opposite directionSystem changes in opposite direction i.e. thermostat in housei.e. thermostat in house crime and punishmentcrime and punishment
Models and Behavior of SystemsModels and Behavior of SystemsTime Delays and SynergyTime Delays and Synergy
Time delaysTime delays -delay b/t input and -delay b/t input and outputoutput Allows problems to build Allows problems to build
slowly so corrective action slowly so corrective action may come too latemay come too late
i.e. smoking and populationi.e. smoking and population SynergySynergy- 2 or more processes - 2 or more processes
interact so their combined effect interact so their combined effect is > than the sum of separate is > than the sum of separate effectseffects i.e. drugs and alcohol, i.e. drugs and alcohol,
people picking up objectpeople picking up object
MatterMatterAtomsAtoms
MatterMatter-anything that has mass and -anything that has mass and takes up spacetakes up space
AtomAtom--basic unit of matter--basic unit of matter Protons—positive, nucleusProtons—positive, nucleus Neutrons—neutral, nucleusNeutrons—neutral, nucleus Electrons—negative, orbitsElectrons—negative, orbits
MatterMatterParts of AtomsParts of Atoms
Protons and NeutronsProtons and Neutrons Together make up an atom’s Together make up an atom’s
atomic mass.atomic mass. ElectronsElectrons
1/1840 of the mass of p’s and n’s1/1840 of the mass of p’s and n’s Moving in orbitals surrounding Moving in orbitals surrounding
the nucleus the nucleus Responsible for chemical Responsible for chemical
properties of atoms (how they properties of atoms (how they react)react)
Atoms--Something to Think AboAtoms--Something to Think About!ut!
MatterMatterElementsElements
ElementElement-pure substance that consists of just one type of -pure substance that consists of just one type of atomatom
114 in the periodic table 114 in the periodic table Atoms have a one or two letter symbolAtoms have a one or two letter symbol Atomic numberAtomic number
Unique to that elementUnique to that element #p’s-- and b/c normally atoms #p’s-- and b/c normally atoms are uncharged also = # e’sare uncharged also = # e’s
Atomic massAtomic mass How much mass an atom hasHow much mass an atom has #p’s + #n’s#p’s + #n’s
CCarbon12.011
6
Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14
6 electrons6 protons6 neutrons
6 electrons6 protons8 neutrons
6 electrons6 protons7 neutrons
Isotopes of Carbon
6MatterMatterIsotopesIsotopes
IsotopesIsotopes-atoms of the same element with different # of -atoms of the same element with different # of neutronsneutronsAtomic number same, atomic mass differentAtomic number same, atomic mass different
MatterMatterRadioactive IsotopesRadioactive Isotopes
Radioactive isotopes-Radioactive isotopes- atoms with unstable atoms with unstable nucleinuclei Break down at constant rate and can Break down at constant rate and can
give off dangerous radiation (type of give off dangerous radiation (type of energy)energy)
Beneficial uses:Beneficial uses: C-14 dating can help geologists date C-14 dating can help geologists date
fossils fossils Cancer treatmentCancer treatment U-235 in nuclear reactorsU-235 in nuclear reactors
MatterMatterBondingBonding
Bonding-Bonding- atoms gain, lose, or share e’s to be stable atoms gain, lose, or share e’s to be stable CompoundCompound- formed by chemical combination of 2 or more - formed by chemical combination of 2 or more
elementselements Bond formation involves outermost e’s Bond formation involves outermost e’s Two types of bondsTwo types of bonds
IonicIonic CovalentCovalent
Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)
Transferof electron
Protons +11Electrons -11Charge 0
Protons +17Electrons -17Charge 0
Protons +11Electrons -10Charge +1
Protons +17Electrons -18Charge -1
Chemical BondsChemical Bonds Ionic bondsIonic bonds
•Ionic bondIonic bond -one or more e’ are transferred -one or more e’ are transferred •Results in formation of ions, or charged atoms that attract to Results in formation of ions, or charged atoms that attract to form an form an ionic compoundionic compound
Chemical BondsChemical BondsCovalent BondsCovalent Bonds
Covalent bonds- Covalent bonds- formed by atoms formed by atoms sharing valence electronssharing valence electrons Stronger than ionic bondsStronger than ionic bonds MoleculeMolecule--forms when atoms --forms when atoms
are joined in a covalent bondare joined in a covalent bond
CompoundsCompounds
Organic-Organic- contain C-C bonds contain C-C bonds Can also have H, O, P, S, N Can also have H, O, P, S, N
and othersand others Natural or synthetic Natural or synthetic InorganicInorganic- don’t have C-C or C-- don’t have C-C or C-
H covalent bondsH covalent bonds NaCl, HNaCl, H22OO
CC
Organic CompoundsOrganic Compounds
Some simple organic molecules can link up, forming C—C Some simple organic molecules can link up, forming C—C bonds- bonds- polymerizationpolymerization Amino acids Amino acids Proteins (meats, enzymes)Proteins (meats, enzymes) Fatty Acids and glycerol Fatty Acids and glycerol Lipids (fats, oils)Lipids (fats, oils) Sugars Sugars Carbohydrates (sugar, starches) Carbohydrates (sugar, starches) Nucleotides Nucleotides Nucleic acids (DNA or RNA) Nucleic acids (DNA or RNA)
Inorganic CompoundsInorganic Compounds No C-C bondsNo C-C bonds Earth’s crust is mostly Earth’s crust is mostly
inorganic minerals and rockinorganic minerals and rock Various combinations of only Various combinations of only
eight elements make up the eight elements make up the bulk of most minerals. bulk of most minerals.
Four States of MatterFour States of Matter Differ in spacing and orderliness of atoms, ions or Differ in spacing and orderliness of atoms, ions or
moleculesmolecules SolidSolid LiquidLiquid GasGas PlasmaPlasma
Most abundant of all states of matter!Most abundant of all states of matter! Forms when enough energy applied to strip away e’, Forms when enough energy applied to strip away e’,
so it’s a mixture of ions and e’so it’s a mixture of ions and e’ Natural forms: sun, stars, lightning and flame Natural forms: sun, stars, lightning and flame Artificial forms: TV, neon signsArtificial forms: TV, neon signs
Matter QualityMatter Quality
High qualityHigh quality Easily accessibleEasily accessible High concentrationHigh concentration Great potential for use as resourceGreat potential for use as resource
Low qualityLow quality Deep underground or difficult to Deep underground or difficult to
collectcollect Low concentrationLow concentration Low potential as a resourceLow potential as a resource
High Quality
Solid
Salt
Coal
Gasoline
Aluminum can
Low Quality
Gas
Solution of salt in water
Coal-fired powerplant emissions
Automobile emissions
Aluminum ore
Law of Conservation of MatterLaw of Conservation of Matter
Physical changesPhysical changes in matter in matter Molecules organized Molecules organized
differently but no change differently but no change in chemical compositionin chemical composition
Cutting foil, melting waterCutting foil, melting water Chemical changesChemical changes
Bonds made or brokenBonds made or broken Burning coal, rustingBurning coal, rusting
ChemicalChemical ChangesChanges
Reactant(s)
carbon + oxygen
C + O2CO2 + energy
carbon dioxide + energy
+ energy
Product(s)
black solid colorless gas colorless gas
C
O
OO OC
Law of Conservation of MatterLaw of Conservation of Matter Law of Conservation of Matter-Law of Conservation of Matter- physical or physical or
chemical changes can’t create or destroy the chemical changes can’t create or destroy the atoms involved. They’re just rearrangedatoms involved. They’re just rearranged
Chemical equations must be balancedChemical equations must be balanced No “away”!!!! -Law tells us there will always be No “away”!!!! -Law tells us there will always be
wastes, pollutants, and toxinswastes, pollutants, and toxins
ToxicologyToxicology
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ToxicologyToxicology -the study of the adverse effects of chemicals or -the study of the adverse effects of chemicals or pollutants on living organisms’ health, specifically humans.pollutants on living organisms’ health, specifically humans.
ToxicityToxicity -a measure of how harmful a substance is and it -a measure of how harmful a substance is and it depends on:depends on:
-Amount of a potentially harmful substance that is -Amount of a potentially harmful substance that is ingested, inhaled, or absorbed through the skin is called ingested, inhaled, or absorbed through the skin is called the the dosedose
-Frequency of exposure-Frequency of exposure-Who is exposed (adult or child)-Who is exposed (adult or child)-How well the body’s detoxification system (liver, kidneys, -How well the body’s detoxification system (liver, kidneys,
etc.) work etc.) work
The resulting type and amount of damage to health areThe resulting type and amount of damage to health arecalled the responsecalled the response
Two types of responses:Two types of responses: Acute-Acute- immediate or rapid harmful reaction immediate or rapid harmful reaction
(dizziness, rash, death)(dizziness, rash, death) Chronic-Chronic- permanent or long–lasting consequence permanent or long–lasting consequence
(asthma, kidney damage, heart disease)(asthma, kidney damage, heart disease)
ToxicologyToxicology
Six major characteristics of a substance determines its toxicity:Six major characteristics of a substance determines its toxicity: 1. Concentration1. Concentration
1ppm= 1 1ppm= 1 ppart pollutant art pollutant pper er mmillion parts of gas, solid or illion parts of gas, solid or liquid it is inliquid it is in
Can Can ↓ pollutant concentration by dumping in larger ↓ pollutant concentration by dumping in larger volume, but there are limitsvolume, but there are limits
2. Solubility2. Solubility Water-soluble- move through the environment and get in Water-soluble- move through the environment and get in
the water supplythe water supply Fat-soluble- penetrate cell membranes and accumulate Fat-soluble- penetrate cell membranes and accumulate
in body tissuein body tissue
Toxicology FactorsToxicology Factors
3. Persistence3. Persistence Some chemicals are resistant to breakdown so have Some chemicals are resistant to breakdown so have
long-lasting harmful effectslong-lasting harmful effects DegradableDegradable (nonpersistent)—broken down by natural, (nonpersistent)—broken down by natural,
physical, chemical or biological processesphysical, chemical or biological processes BiodegradableBiodegradable—broken down by living organisms—broken down by living organisms Slowly degradableSlowly degradable (persistent) (persistent)
Decades Decades Plastics, DDTPlastics, DDT
NondegradingNondegrading—lead, mercury, arsenic—lead, mercury, arsenic
Toxicology FactorsToxicology Factors
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• 4. Bioaccumulation4. Bioaccumulation results results when the concentration of a when the concentration of a chemical in tissues of an chemical in tissues of an organism is higher than organism is higher than would normally be expected.would normally be expected.
• 5. Biomagnification 5. Biomagnification involves magnification of involves magnification of concentrations as they pass concentrations as they pass through the food chains and through the food chains and webs.webs.
Toxicology FactorsToxicology Factors
6. Chemical Interactions6. Chemical Interactions Antagonistic interactions reduce harmful effectsAntagonistic interactions reduce harmful effects
Vitamin A, D and E apparently reduce some Vitamin A, D and E apparently reduce some cancer-causing chemicalscancer-causing chemicals
Synergistic interactions multiplies harmful effectsSynergistic interactions multiplies harmful effects Asbestos workers have a 20-fold increased Asbestos workers have a 20-fold increased
chance of getting lung cancer, but if they chance of getting lung cancer, but if they smoke they have a 400-fold increasesmoke they have a 400-fold increase
Toxicology FactorsToxicology Factors
Determining ToxicityDetermining Toxicity
Determining toxicity:Determining toxicity:
• Case reports (usually to physicians) Case reports (usually to physicians)
• Epidemiology- studies of populations exposed Epidemiology- studies of populations exposed
• Laboratory investigations (usually with test animals)Laboratory investigations (usually with test animals)
- LDLD5050 (median (median llethal ethal ddose)ose) -amt of a chemical that kills 50% -amt of a chemical that kills 50%
of animals (rats) in a test population (60–200 animals) in 2 of animals (rats) in a test population (60–200 animals) in 2 weeks weeks
- A A poisonpoison is legally defined as a chemical that has an is legally defined as a chemical that has an LDLD5050
≤≤50 mg chemical/kg body weight50 mg chemical/kg body weight
***Higher LD50, less toxic the substance is***Higher LD50, less toxic the substance is
ToxicityToxicityToxicityToxicity LDLD5050 Lethal DoseLethal Dose ExamplesExamples
Super Super < 0.01< 0.01 less than 1 drop less than 1 drop dioxin, botulismdioxin, botulismmushroomsmushrooms
Extreme Extreme <5<5 less than 7 drops less than 7 drops heroin, nicotineheroin, nicotine
Very Very 5-505-50 7 drops to 1 tsp. 7 drops to 1 tsp. morphine, codeinemorphine, codeine
ToxicToxic 50-50050-500 1 tsp. 1 tsp. DDT, H DDT, H22SOSO44, ,
CaffeineCaffeine
Moderate Moderate 500-5K500-5K 1 oz.-1 pt.1 oz.-1 pt. aspirin, wood aspirin, wood alcoholalcohol
SlightlySlightly 5K-15K 5K-15K 1 pt. 1 pt. ethyl alcohol, soapsethyl alcohol, soaps
Non-ToxicNon-Toxic >15K>15K >1qt.>1qt. water, table sugar water, table sugar***Higher LD50, less toxic the substance is***Higher LD50, less toxic the substance is
(LD50 measured in mg/kg of body weight)(LD50 measured in mg/kg of body weight)
Dose–Response CurvesDose–Response Curves
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Dose–response curves-Dose–response curves- show the adverse effects of show the adverse effects of various doses of a toxic agent on a test population by various doses of a toxic agent on a test population by plotting harmful effect as a function of dose.plotting harmful effect as a function of dose.
The left dose–The left dose–response curve response curve shows increasing shows increasing harmful effects with harmful effects with dose, and no dose dose, and no dose is considered safe. is considered safe.
The right example The right example has a threshold, has a threshold, such that low doses such that low doses are considered safe.are considered safe.
Why so little is known of toxicityWhy so little is known of toxicity Only 10% of at least 75,000 commercial chemicals have Only 10% of at least 75,000 commercial chemicals have
been screenedbeen screened ~2% determined to be carcinogen, teratogen or mutagen~2% determined to be carcinogen, teratogen or mutagen >1000 new synthetic chemicals added per year>1000 new synthetic chemicals added per year >99.5% of US commercial chemicals are NOT regulated>99.5% of US commercial chemicals are NOT regulated
ToxicityToxicity
Chemical HazardsChemical Hazards
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What are toxic vs. hazardous chemicals?What are toxic vs. hazardous chemicals?
• Toxic (poisonous) chemicals-Toxic (poisonous) chemicals- substances that are fatal substances that are fatal to over 50% of test animals (LDto over 50% of test animals (LD5050) at given ) at given
concentrationsconcentrations
• Hazardous chemicalsHazardous chemicals- cause harm by- cause harm by
- Flammable or explosive (e.g., gasoline)Flammable or explosive (e.g., gasoline)
- Irritating or damaging the skin or lungs (e.g., strong Irritating or damaging the skin or lungs (e.g., strong acids or alkalines such as oven cleaners)acids or alkalines such as oven cleaners)
- Interfering with or preventing oxygen uptake and Interfering with or preventing oxygen uptake and distribution (e.g., carbon monoxide, CO)distribution (e.g., carbon monoxide, CO)
- Inducing allergic reactions Inducing allergic reactions
Hazardous chemicalsHazardous chemicals
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• Mutagens-Mutagens- cause random mutations, or changes in the cause random mutations, or changes in the DNADNA
• Teratogens-Teratogens- cause birth defects cause birth defectse.g., PCBs, steroid hormones, heavy metals, rubella, e.g., PCBs, steroid hormones, heavy metals, rubella, mercury in water, fetal alcohol syndrome and crack mercury in water, fetal alcohol syndrome and crack babiesbabies
• Carcinogens-Carcinogens- cause cancer cause cancer- over 100 types of cancer (depending on cells involved)over 100 types of cancer (depending on cells involved)- e.g., cigarette smoke.e.g., cigarette smoke.
- Hormone disruptersHormone disrupters
Hormone DisruptersHormone Disrupters
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HormonesHormones -molecules that act -molecules that act as messengers in the as messengers in the endocrine system to regulate endocrine system to regulate reproduction, growth and reproduction, growth and development. development.
Hormone disrupters (mimics Hormone disrupters (mimics and blockers), attach to and blockers), attach to receptors and disrupt/alter receptors and disrupt/alter development.development.
Hormone DisruptersHormone Disrupters
© Brooks/Cole Publishing Company / ITP
• 51 chemicals, many widely used, have been 51 chemicals, many widely used, have been shown to be hormone disrupters on wildlife, shown to be hormone disrupters on wildlife, laboratory animals and humanslaboratory animals and humans
- i.e. dioxins, certain PCBs, various chemicals in i.e. dioxins, certain PCBs, various chemicals in plastics, some pesticides, lead and mercuryplastics, some pesticides, lead and mercury
• 1997 study shows that sperm count of men in 1997 study shows that sperm count of men in U.S. and Europe has declined 50%.U.S. and Europe has declined 50%.
EnergyEnergy
EnergyEnergy- capacity to do work and - capacity to do work and transfer heattransfer heat
Measured in calories = amt of Measured in calories = amt of heat required to raise the temp of heat required to raise the temp of 1.0g of water 11.0g of water 1ooCC
Work is movement of matter Work is movement of matter (pump gas through pipe, move (pump gas through pipe, move book)book)
EnergyEnergy
Two typesTwo types KineticKinetic
Energy in motionEnergy in motion Possessed by matter b/c of its Possessed by matter b/c of its
mass and speed (velocity)mass and speed (velocity) PotentialPotential
Stored energyStored energy Potential to be changed into Potential to be changed into
kinetic energykinetic energy Rock in hand, unlit match, energy Rock in hand, unlit match, energy
stored in bonds of foodstuff, water stored in bonds of foodstuff, water behind dambehind dam
Sun
High energy, shortwavelength
Low energy, longwavelength
Ionizing radiation Nonionizing radiation
Cosmicrays
Gammarays
X rays Farultraviolet
waves
Nearultraviolet
waves
VisibleNear
infraredwaves
Farinfraredwaves
Microwaves TVwaves
Radiowaves
10-14 10-12 10-8 10-7 10-6 10-5 10-3 10-2 10-1 1
•Electromagnetic radiation (EM)-Electromagnetic radiation (EM)- energy traveling in waves as energy traveling in waves as a result of changing electric and magnetic fieldsa result of changing electric and magnetic fields•Different forms with different wavelengths and energy contentDifferent forms with different wavelengths and energy content•Electromagnetic Radiation Movie
EnergyEnergyElectromagnetic radiationElectromagnetic radiation
EnergyEnergyElectromagnetic radiationElectromagnetic radiation
Two types of EM radiationTwo types of EM radiation Ionizing EM radiationIonizing EM radiation
High energyHigh energyknock e’s from knock e’s from atoms and change them to + ionsatoms and change them to + ions
e’s and ions disrupt living cells-e’s and ions disrupt living cells-cancercancer
Non-ionizing EM radiationNon-ionizing EM radiation Low energy Low energy Not highly reactive Not highly reactive
or as dangerous.or as dangerous. Visible light-- makes up most of Visible light-- makes up most of
the spectrum of EM radiation the spectrum of EM radiation from the sun.from the sun.
EnergyEnergyHeatHeat
HeatHeat- total kinetic energy of all - total kinetic energy of all moving atoms, ions or moleculesmoving atoms, ions or molecules
TemperatureTemperature—average speed of —average speed of motion of the atoms, ions or motion of the atoms, ions or molecules in mattermolecules in matter
Atoms move faster when heatedAtoms move faster when heated Heat energy flows hot Heat energy flows hot cold cold Hot air/water less dense due to Hot air/water less dense due to
energy so rises.energy so rises.
Energy Energy QualityQuality
Energy quality-Energy quality- measure of energy source’s measure of energy source’s ability to do useful workability to do useful work High qualityHigh quality
ConcentratedConcentrated Can perform much useful workCan perform much useful work Chemical energy in coal and gas, Chemical energy in coal and gas,
sunlightsunlight Low qualityLow quality
DispersedDispersed Little ability to do workLittle ability to do work Heat in atmosphere or heat in oceansHeat in atmosphere or heat in oceans
Energy LawsEnergy Laws11stst Law of Thermodynamics Law of Thermodynamics
11stst law of thermodynamics law of thermodynamics (Law of conservation of (Law of conservation of energy) energy) In all physical and chemical changes, energy is not In all physical and chemical changes, energy is not
created or destroyed, but changes formcreated or destroyed, but changes form Total energy of system remains constantTotal energy of system remains constant
Energy LawsEnergy Laws22ndnd Law of Thermodynamics Law of Thermodynamics
22ndnd Law of Thermodynamics Law of Thermodynamics (Law of (Law of disorder)disorder) When energy changed from one form When energy changed from one form
to another, useful energy is degraded to another, useful energy is degraded to lower quality, more dispersed, less to lower quality, more dispersed, less useful energyuseful energy
Light bulb---95% lost as waste heatLight bulb---95% lost as waste heat Energy stored in food---most lost as Energy stored in food---most lost as
waste heatwaste heat **We can never recycle or reuse **We can never recycle or reuse
high-quality energy to perform useful high-quality energy to perform useful workwork
Solarenergy
Wasteheat
Chemicalenergy
(photosynthesis)
Wasteheat
Wasteheat
Wasteheat
Chemicalenergy(food)
Mechanicalenergy
(moving,thinking,
living)
Nuclear ChangesNuclear Changes
Matter can undergo physical, chemical OR nuclear Matter can undergo physical, chemical OR nuclear changeschanges
Nuclear change-Nuclear change--nucleus of certain isotopes -nucleus of certain isotopes spontaneously change or are made to change into nuclei spontaneously change or are made to change into nuclei of different isotopesof different isotopes
Matter Matter Energy Energy 3 types of nuclear change3 types of nuclear change
Radioactive decayRadioactive decay Nuclear fissionNuclear fission Nuclear fusionNuclear fusion
Nuclear ChangesNuclear ChangesRadioactive DecayRadioactive Decay
Radioactive isotopes with unstable nuclei decayRadioactive isotopes with unstable nuclei decay Particles and/or damaging ionizing radiation, emitted Particles and/or damaging ionizing radiation, emitted
until nuclei stable and not radioactiveuntil nuclei stable and not radioactive Gamma raysGamma rays Genetic damage to DNAGenetic damage to DNA Somatic damage to tissuesSomatic damage to tissues
Nuclear ChangesNuclear ChangesRadioactive DecayRadioactive Decay
Radioactive isotopes decay at Radioactive isotopes decay at a characteristic fixed rate a characteristic fixed rate called a called a half-life (thalf-life (t1/21/2)) Time for half the nuclei in a Time for half the nuclei in a
sample to decaysample to decay Can’t be changed due to T, Can’t be changed due to T,
P, or chemical rxnsP, or chemical rxns Used to estimate time a Used to estimate time a
sample of radioisotope sample of radioisotope must be stored safely must be stored safely before it decays to a safe before it decays to a safe level level half-life X 10half-life X 10
Table 3-1 Half-Lives of Selected Radioisotopes
Isotope
Potassium-42
Iodine-131
Cobalt-60
Hydrogen-3 (tritium)
Strontium-90
Carbon-14
Plutonium-239
Uranium-235
Uranium-238
Radiation Half-Life
12.4 hours
8 days
5.27 years
12.5 years
28 years
5,370 years
24,000 years
710 million years
4.5 billion years
Emitted
Alpha, beta
Beta, gamma
Beta, gamma
Beta
Beta
Beta
Alpha, gamma
Alpha, gamma
Alpha, gamma
Nuclear ChangesNuclear ChangesNuclear FissionNuclear Fission
FissionFission—splitting of nuclei—splitting of nuclei Nuclei of isotopes with large Nuclei of isotopes with large
masses split into lighter masses split into lighter nuclei when struck by nuclei when struck by neutronsneutrons
Release energy and more Release energy and more neutrons setting off a chain neutrons setting off a chain reactionreaction
Atomic bomb and nuclear Atomic bomb and nuclear power plants power plants
Fission fragment
Fission fragment
Energy
n n
n
n
Uranium-235nucleus
Unstablenucleus
Energy
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
Nuclear ChangesNuclear ChangesNuclear FusionNuclear Fusion
FusionFusion—joining of nuclei—joining of nuclei Isotopes of light elements are Isotopes of light elements are
forced together at high T’s until forced together at high T’s until they fuse into a heavier nucleusthey fuse into a heavier nucleus
Harder to accomplish than Harder to accomplish than fission, but releases more fission, but releases more energyenergy
Fusion of H nuclei to form He Fusion of H nuclei to form He nuclei is a source of energy for nuclei is a source of energy for sun and starssun and stars
H bombsH bombs
Fuel Reaction Conditions Products
D-T Fusion
Hydrogen-2 ordeuterium nucleus
Hydrogen-3 ortritium nucleus
+
+
Neutron
Energy
+ +
Helium-4nucleus
++
100 million ˚C
Neutron
Proton+
Matter and Energy LawsMatter and Energy LawsEnvironmental ProblemsEnvironmental Problems
Law of conservation of matter and 1Law of conservation of matter and 1stst and 2 and 2ndnd law of law of thermodynamics together mean individual resource use thermodynamics together mean individual resource use adds waste matter and heat to the environmentadds waste matter and heat to the environment
Different types of economic systemsDifferent types of economic systems High-throughput, high waste economiesHigh-throughput, high waste economies Matter-recycling-and-reuse economyMatter-recycling-and-reuse economy Low-throughput economyLow-throughput economy
Matter and Energy LawsMatter and Energy LawsEnvironmental ProblemsEnvironmental Problems
High-throughput EconomyHigh-throughput Economy Developed countries with ever increasing growthDeveloped countries with ever increasing growth Increased one-way flow of matter through systems and Increased one-way flow of matter through systems and
out to planetary “sinks”--air, water, soil, and organismsout to planetary “sinks”--air, water, soil, and organisms Pollutants and wastes accumulatePollutants and wastes accumulate Output will exceed environment’s capacity to dilute Output will exceed environment’s capacity to dilute
and degrade waste matter and absorb heatand degrade waste matter and absorb heat UNSUSTAINABLE!UNSUSTAINABLE!
Matter and Energy LawsMatter and Energy LawsEnvironmental ProblemsEnvironmental Problems
Low-Throughput EconomyLow-Throughput Economy Decrease matter and energy flowDecrease matter and energy flow Don’t waste matter and energy resourcesDon’t waste matter and energy resources Recycle and reuseRecycle and reuse Stabilize populationStabilize population