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CHAPTER 2 SCIENCE, SYSTEMS, MATTER AND ENERGY EASTER ISLAND CASE STUDY—EASTER ISLAND Collapse due to obsession with stone gods Unsustainable use of resources—forests of giant palms (shelter, tools, canoes to fish) and basswoods (hauhau) for burning to cook and keep warm, fibers to make ropes https://www.youtube.com/watch?v=5DBTtC 4J0OY EASTER ISLAND—TRAGEDY OF THE COMMONS NO TREES 1. Could not build canoes, leave island 2. Springs dry up because of no absorption of water and slow water release 3. Soil erosion, crops failed causing famine 4. No wood for cooking, warmth 5. Devoured all seabirds and landbirds SCIENTIFIC METHOD Skepticism, peer review, reproducibility Hypothesis—testable, proposed solution Experiment 1. Control—standard to compare 2. Constants—factors that remain the same 3. Manipulated variable—factor being tested 4 Responding variable—results READING QUIZ—PP. 34-47 Atoms—basic building block of matter that retains properties of the substances 1. Protons—positive particles in nucleus that identifies element (atomic number) 2. Neutrons—neutral particle in nucleus that together with protons make atomic mass number http://41.media.tumblr.com/37ebe403689414269ccad2b5675e334d/tumblr_m mix7dm0b21res364o1_1280.jpg MATTER Elements—only one kind of atom represented by symbol 96.3% of body weight is CHNO Molecules—2 or more atoms chemically combined Compound—2 or more DIFFERENT atoms chemically combined represented by formula http://3.bp.blogspot.com/_8RHzyAodrNI/TKggoNTmxEI/AAAAAAAAAC g/FEtGkaBzSD4/s1600/elementsAndCompounds.gif FORMULAS TO KNOW NaCl, H2O, O2, O3, N2, N2O (nitrous oxide), NO (nitric oxide), H2S, CO, CO2, NO2 (nitrous dioxide), SO2, NH3, H2SO4, HNO3 (nitric acid), CH4, C6H12O6 DIFFERENT FORMS OF ATOMS Isotopes—different number of neutrons but same number of protons Ions—atom that has lost/gained electrons Positive—lost electrons Negative—gained electrons http://iqa.evergreenps.org/science/phy_science/isotopes_files/nn3.gif http://gcserevision101.files.wordpress.com/2009/02/halogenionic-bond.jpg ORGANIC MOLECULES Contain at least 2 carbons bonded together with H, O, N, S Most chemicals making up body, vitamins, plastics, aspirin, penicillin CH4—Methane is exception of organic molecule with only 1 carbon Hydrocarbons—C to H ORGANIC MOLECULES Chlorinated hydrocarbons—DDT insecticide, C14H9Cl5 Simple carbohydrates—glucose, fructose, galactose C6H12O6 http://www.nutrientsreview.com/wp-content/uploads/2014/09/Glucoseformula.jpg http://www.davistownmuseum.org/cbm/chemicals/ddt. jpg CELLS Prokaryotes No nucleus, no membrane-bound organelles, contains ribosomes, single strand of circular DNA, single cell bacteria, simple, small Eukaryotes—Nucleus, many double membrane-bound organelles, large DNA in nucleus, more complex, larger http://img.youtube.com/vi/9o6huiw7u5o/0.jpg MACROMOLECULES Polymers made of monomers linked together Complex carbohydrates Cellulose—plant cell wall structure Starch—plant energy storage Chitin—animal structure of exoskeleton Glycogen—animal energy storage in liver and muscle http://thumbs.dreamstime.com/z/cicada-shell-white3336393.jpg http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.Fre eContent.ImageService.svc/ImageService/Articleimage/2012/PY/c1 py00445j/c1py00445j-f1.gif MACROMOLECULES Proteins—made of amino acids Nucleic acids—made of nucleotides DNA chromosomes genes RNA carries DNA code to ribosome to create protein Lipids—no monomer; long term energy storage and composition of cell membranes STATES AND CHANGES IN MATTER States—solid, liquid, gas, plasma Artificial plasma—pass electricity through gas to make fluorescent light, neon signs, TV/computer screens Matter Quality—how useful a form of matter is based on availability and concentration http://www.assignmenthelp.net/assignment_help/images/chemistry/states-of-matter/stateof-matter-assignment-help.PNG MATTER QUALITY High-quality matter—concentrated, near earth’s surface; great potential as resource (aluminum cans) Low-quality matter—dilute, deep underground or dispersed in ocean, atmosphere; little potential as resource (aluminum ore) CONSERVATION OF MATTER Chemical changes create energy and waste Pollutants—Severity of harmful effects 1. Concentration—substance per given volume 2. Persistence—how long pollutant stays in air, water, soil, body PERSISTENCE Degradable—broken down completely or reduced to acceptable levels by natural processes Biodegradable—broken down by living things (bacteria)—sewage plants Slow to degrade—takes decades or longer such as DDT/most plastics Nondegradable—is not broken down by natural processes (lead, mercury, arsenic) http://i00.i.aliimg.com/photo/v0/50006811122_4/Bioclean_co mpost_for_biodegradable_waste_products_from.jpg http://vietnamnews.vn/ImageHand ler.ashx?ThumbnailID=125080 http://www.mhhe.com/biosci/genbio/enger/student/olc/art_quizze s/genbiomedia/0414.jpg NUCLEAR CHANGES Radioactive decay—emission of alpha/beta particles, gamma rays, or both at fixed rate Half-life—characteristic rate of decay different isotopes time needed for one half of nuclei in given quantity of isotope to decay and emit radiation NUCLEAR CHANGES Half-life estimates how long radioisotopes sample must be safely stored Approx. 10 half-lives I-131 (concentrates in thyroid) has half-life of 8 days (protection needed for 80 days) Plutonium-239 (lung cancer) in nuclear reactors has half-life of 24,000 years (10 X 24,000) = 240,000 years ENERGY—CASE STUDY Ability to do work Today—person uses 2,000 kcal/day for basic needs plus 600,000 kcal/day used by machines and systems for lifestyle History Fire (hunters/gathers) cooked, light heat Farmers—animal power for plowing, transport, carrying loads ENERGY—CASE STUDY Wind— Pump water, transport, flowing water to transport goods/people, mills for grinding grains, produce electricity Steam engine—firewood 91% of energy used until depletion of forests 1850 Coal—factories, heating 1800—18% wood, 73% coal ENERGY—CASE STUDY 1900 40% oil, 38% coal, 18% natural gas 1950 Nuclear Today—82% nonrenewable resources 33% oil, coal 22%, natural gas 21% 6% nuclear, 11% wood/biomass 7% flowing water, geothermal, sun, wind http://wesrch1.wesrch.com/User_images/wiki/2fb8b474ae494b70b2b bca47c7db2048_1236984472.jpg ENERGY LAWS First Law of Thermodynamics Energy cannot be created or destroyed Also known as Law of Conservation of Energy Second Law of Thermodynamics Energy quality always decreases with every energy change to decrease useful energy EXAMPLES OF SECOND LAW Driving vehicles—approx. 6% high-quality gas energy actually moves car; 94% degraded and lost as heat Electrical energy—light bulbs 5% useful energy; 95% low-quality heat loss Solarchemical of photosynthesischemical in foodsmechanical for moving (each change loses heat energy ENERGY CANNOT BE RECYCLED Energy efficiency (productivity)—measure of how much useful work is accomplished by input of energy Approx. 16% of used energy in U.S. ends in useful work Approx. 84% wasted unavoidably with 41% due to Second Law and unnecessarily wasted with 43% SUSTAINABILITY Cheapest, quickest solution to get more energy is to STOP wasting with gasefficient vehicles, well-insulated houses, energy efficient lights, heat/cool, appliances Ideally, use of solar, hydropower, wind, geothermal biofuels SUSTAINABILITY? Most nations increase economic growth by creating goods/services Adds large amounts of waste, pollution, lowquality heat Pooling of pollutants in sinks (soil, water, body, air) which increases harmful levels UNSUSTAINABILIY