Chapter 3 Matter and Energy Resources Types and Concepts

1. Chapter 3Matter and Energy Resources Types and Concepts

2. Science, Technology and Environmental Science • What is science? • An attempt to discover order in nature then use the knowledge to make predictions about nature • Asks what events occur in nature over and over • Asks why things happen a certain way • Does NOT establish absolute truth about nature • What to scientists do? • Observe, measure, and collect data • “Science is built up of facts, but a collection of facts is no more science than a heap of stones is a house.” • Hypothesis vs. theory

3. Scientific Methods • Ways to gather data and formulate and test hypothesis and theories by following a series of steps to arrive at a conclusion • Define a problem and collect background information about the problem • Form a hypothesis (IF……THEN….statement) • Test the hypothesis • Identify the variables • Independent variable • Dependent variable • Constant or standardized variables • Control • Gather data and arrange it in tables and charts to be graphed • Interpret and analyze the data • Form a conclusion by falsifying or supporting your hypothesis • Report it by publishing results • Control Experiments • Double blind experiments

4. Technology vs. Pure Science • Creation of new products and processes that are supposed to improve our: • Chances for survival • Our comfort level • Our quality of life • Some technologies were invented long before anyone knew the science behind them • Aspirin • Photography • Crossbreeding of farm animals • Pure science research is published and passed around freely to be tested by others as opposed to newly discovered technologies which are kept secret to avoid competition from other companies and are usually not tested enough to eliminate possible consequences

5. Environmental Science • The study of how we and other species interact with one another and the nonliving environment • Integrates knowledge from: • Physics • Chemistry • Biology • Ecology • Geology • Geography, • Resource technology • Engineering • Resource conservation • Demography • Economics • Politics • ethics

6. Matter: Forms, Structure, and Quality • Nature’s building blocks • Matter • Elements • Symbols • formulas • Compounds • Two or more atoms chemically combined which can only be separated by chemical means • Chemical formula used to show atoms of each type to show its structure • Subscript shows the number of atoms in the compound such as H2O • Mixtures • 4 physical states • Atoms • Ions • molecules

7. Atoms and Ions • Atomic structure • Nucleus • Proton - positive • Neutron - neutral • Electron – negative • Energy level or electron cloud • Suborbitals – found within the electron cloud of the second and remaining energy levels • Valence electrons • Atomic number • Atomic mass number • Isotopes • Based on number of neutrons added to the nucleus • Hydrogen • Ions – atoms that either gain or lose electrons • Cations • Anions • Forms ionic bonds

8. Matter Quality • Measure of how useful a matter resource is based on availability • High quality matter – organized and concentrated and usually found near the Earth’s surface • Low quality matter – disorganized, dilute, or dispersed and is often found deep underground or dispersed in the ocean or atmosphere • Takes less energy, water and money to recycle an aluminum can than to make a new can from aluminum ore

9. Energy: Types, Forms, and Quality • Capacity to do work • Heat that flows automatically from a hot object to a cold object • Comes in many forms • Light, heat, electricity • Stored in chemical bonds in coal, sugar, etc. • Moving water, wind and joggers • Nuclear energy emitted from nuclei of certain isotopes

10. Kinetic Energy • Energy matter has because of its motion and mass • Wind, flowing streams, falling rocks, heat, electricity, moving cars • Radio waves, TV waves, microwaves, infrared radiation, visible light, UV rays, X-rays, gamma rays, and cosmic rays and are known as electromagnetic radiation • Cosmic rays, gamma rays, X-rays and UV rays have enough energy to knock electrons from atoms and change them into positively charged ions and are called ionizing radiation which can interfere with body processes and cause cancer • Other forms of electromagnetic radiation do not contain enough energy to form ions and are called nonionizing radiation • TV set radiation, video displays on computers, electric blankets, and water beds may cause cancer but scientists disagree on this issue

11. Potential Energy • Stored energy available for use • A rock in your hand • Unlit stick of dynamite • Still water behind a dam • Nuclear energy stored in the nuclei of atoms

12. Energy Chain • When you flip a light switch you are at the end of an energy chain • Electric power plant burns a fuel to make heat • The heat is used to boil water to make steam • The steam expands through turbines, where the thermal energy is converted to kinetic energy • The turbines turn generators, and electromagnetic energy – electricity – comes out and is transmitted by wire to factories and buildings

13. Energy Resources Used by People • 99% of energy used to heat the Earth comes from the sun • Solar energy recycles carbon, oxygen, water and other chemicals we and other organisms use for life • Includes energy directly from the sun • Includes indirectly wind, falling and flowing water (hydropower) and biomass (stored in chemical bonds of plants) • 99% of solar power is not sold in the market place • 1% is generated to supplement solar output as either commercial energy or noncommercial energy • Noncommercial energy is used by people who gather fuelwood, dung and crop wastes for their own use • Used mainly by LDCs • Commercial energy comes from extracting and burning mineral resources in the Earth’s crust, primarily the fossil fuels • Used mainly by MDCs

14. Energy Quality • Energy quality • Measure of energy’s ability to do useful work • High quality energy • Organized or concentrated and can perform a great deal of useful work • Electricity, coal, gasoline • Concentrated sunlight, nuclei of U-235 • Low quality energy • Disorganized or dispersed and has little ability to do useful work • Heat dispersed in the moving molecules of a large amount of matter such as the ocean or atmosphere • Makes sense to match the quality of an energy source to the quality of the energy needs to perform a particular task – saves energy and money

15. Physical and Chemical Changes • Physical and chemical changes • Physical change is one that involves no change in chemical composition • Cutting aluminum foil into pieces • Changing a substance from one state to another • Chemical change, or chemical reaction, is a change where there is a change in the chemical composition of the elements and compounds • Equations are used to show chemical reactions with the reactants and products of a reaction • C + O2 CO2 + energy

16. Law of Conservation of Matter • We take materials from the Earth, use them, discard them, burn them, bury them, reuse them, or recycle them • In most cases, all physical and chemical changes don’t create or destroy any of the atoms in matter, just transform them – the First Law or Conservation of Matter • Everything we throw away is still with us in one form or another • We can remove substances from polluted water at a sewage treatment plant, but the gooey sludge must either be burned (producing air pollution), buried (possibly contaminating groundwater), or cleaned up and applied to the land as fertilizer (dangerous if it contains nondegradable toxic metals such as Pb or Hg)

17. Banning pesticides like DDT in the U.S. but still selling it abroad usually comes back to the U.S. on residues of imported coffee or fruit or by deposition from air masses moved by winds – something environmentalists call the circle of poison • Law of conservation of matter means we will always be faced with the problem of what to do with some quality of wastes • Pollution prevention and waste reduction can greatly reduce the amount of wastes we add to the environment

18. Nuclear Changes • Nuclear radioactivity • Nuclear change occurs when nuclei of certain isotopes spontaneously change or are forced to change into one or more different isotopes • Natural radioactive decay is a nuclear change in which unstable isotopes spontaneously shoot out fast-moving particles, high energy radiation, or both at a fixed rate • Unstable isotopes are called radioactive isotopes or radioisotopes • Radioactive decay continues into a new, stable isotope which is not radioactive • Radiation emitted by radioisotopes is damaging ionizing radiation • Gamma rays are a form of high-energy electromagnetic radiation • Alpha particles are fast-moving, positively charged chunks of matter that consists of 2 protons and 2 neutrons • Beta particles are high speed electrons

19. Half - Life • The time needed for one-half of the nuclei in radioisotopes to emit its radiation and become a different isotope • Used to estimate how long a sample of a radioisotope must be stored in a safe enclosure before it decays to what is a safe level • Plutonium-239, which can cause lung cancer, must be stored safely for 240,000 years – 6 times longer than the latest version of our species has existed

20. Nuclear Fission • Nuclear fission – a nuclear change in which nuclei of certain isotopes with large mass numbers (U-235) are split apart into lighter nuclei when struck with neutrons and energy • For each fission to occur, there must be enough fissionable nuclei present to provide the critical mass needed for efficient capture of these neutrons • Multiple fissions within a critical mass form a chain reaction, which releases an enormous amount of energy • Living cells can be damaged by ionizing radiation given off by the radioactive lighter nuclei • In an atomic or nuclear bomb, an enormous amount of energy is released in a fraction of a second in an uncontrolled nuclear chain reaction • In areactor of a nuclear power plant the rate at which the nuclear fission chain reactions take place is controlled so that the heat produced is used to produce high-pressure steam which spins turbines, which in turn generate electricity • If the chain reactions go out of control a meltdown can occur which lead to disasters such as the one that occurred at Chernobyl

21. Nuclear Fusion • Nuclear fusion is a nuclear change in which two isotopes of light elements, such as hydrogen, are forced together at extremely high temperatures until they fuse to form a heavier nucleus, releasing energy in the process • Harder to initiate because it needs temperatures of 100 million degrees C to start • But once started, it releases far more energy per unit of fuel than does fission • Nuclear fusion of hydrogen to form helium is the source of energy in the sun and other stars • After WWII the principle of uncontrolled nuclear fusion was used to develop extremely powerful weapons called thermonuclear weapons • Uses the D-T fusion reaction in which H-2 (deuterium) nucleus and an H-3 (tritium) nucleus are fused together to form a form a helium-4 nucleus, a neutron and energy • Scientists are trying to develop controlled nuclear fusion in which the D-T reaction is used to produce heat that can be converted into electricity but will not be a practical source of energy until the year 2050

22. The Two Ironclad Laws of Energy • First law of Thermodynamics – energy can neither be created nor destroyed only transformed • Second law of Thermodynamics – when energy is converted to another form, there is a decrease in energy quality and the degraded energy is usually in the form of waste heat called entropy • Second law says that we cannot recycle energy or reuse high-quality energy because it becomes dispersed into the environment • Matter cycles and energy flows only in one direction

23. Life and the Second Law of Energy • In order for your body to function properly, you must continually get and use high-quality matter and energy from your surroundings • As you use these, you continuously add low-quality heat (entropy) equal to a 100 watt bulb to the environment • You give off molecules of CO2 and H2O vapor which is dispersed into the atmosphere • Enormous amounts of low-quality heat and waste matter are added to the environment when deposits of minerals and fuels are extracted from the Earth’s crust, processed, and used to make roads, clothes, etc. • That is why reducing energy waste and switching from harmful nonrenewable energy resources to less harmful renewable energy sources are the keys to a sustainable future

24. Throw-Away Societies • What you add to the environment may seem insignificant, but you are only 1 of 1.4 billion people in MDCs using large quantities of matter • Most of today’s advanced industrialized countries are largely high-waste societies, or throwaway societies, sustaining ever-increasing economic growth by increasing the flow of throughput of planetary resources • These resources flow through the economy to planetary sinks (air, water, soil, organisms) where pollutants can build up • If more and more people use and waste more and more energy, sooner or later we will exceed the capacity of the environment to dilute and degrade waste

25. Matter-Recycling Societies • One solution to the problem of waste is to convert from a throwaway society to matter-recycling society so that economic growth can continue without depleting matter resources and producing excessive pollution • Recycling matter saves energy but it always requires high-quality energy, which cannot be recycled • In the long run, a matter-recycling society based on continuing population growth will not work • You can only recycle some things up to a point where it will no longer by useable • More and more people will only require using more resources

26. Low Throughput Economies • The three scientific laws governing matter and energy changes suggest that the best long term solution to our environmental and resource problems is to shift to an economy that maximizes matter and energy flow (throughput) to a more sustainable low-throughput (low waste) economy • We must work with Nature not against it