Science, Systems, Matter, and Energy G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 3 G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 3

Key Concepts  Science as a process for understanding  Components and regulation of systems  Matter: forms, quality, and how it changes; laws of matter  Nuclear changes and radioactivity  Energy: forms, quality, and how it changes; laws of energy

Science, and Critical Thinking  Scientific data  Scientific (natural) laws  Consensus science  Scientific theories  Scientific hypotheses  Frontier science Ask a question Do experiments and collect data Formulate hypothesis to explain data Do more Experiments to test hypothesis Revise hypothesis if necessary Well-tested and accepted hypotheses become scientific theories Interpret data Well-tested and accepted patterns In data become scientific laws Fig. 3-2 p. 41

Models and Behavior of Systems  Inputs- matter, energy, information  Flows (throughputs) – of matter or energy  Stores (storage areas) – place where energy or matter can accumulate for various lengths of time (your body, water on earth)  Stores (storage areas) – place where energy or matter can accumulate for various lengths of time (your body, water on earth)  Outputs- certain forms of matter or energy leave the system and sink or absorbs into the environment (air, water, soil)  Outputs- certain forms of matter or energy leave the system and sink or absorbs into the environment (air, water, soil)

System Regulation  Positive Feedback  Negative Feedback  Homeostasis  Time Delay – corrective action can be too late -smokers  Time Delay – corrective action can be too late -smokers  Synergy Fig. 3-3 p. 46

Feedback Loops Positive Feedback- ex: collecting interest in a bank account. Negative feedback- ex: thermostat in a house, when the house reaches or exceeds the set temp, the air shuts off.

Threshold Level Point when a fundamental shift occurs Ex: your body becomes so overheated that you pass out. Your body has a threshold temperature and when it is reached, there is a change Ex: Easter Island exceeded threshold of resource use. Time delays can slow negative feedback and more rapidly approach threshold levels – population growth, unknown pollution, degradation of forests from air pollution.

Mt. Mitchell –Acid Rain Damage

Law of Conservation of Problems The solution to one problem usually creates one or more new problems Ex: chemical fertilizers –increases crop productivity, can become widespread, new problem of overstimulation of non-target plants and pollution to water supply Do benefits outweigh potential harm? Not enough data Imperfect models Different assumptions

Environmental Surprises Result of Shifts when threshold is met Synergistic interaction Unpredictable or natural events (weather, invasives) Strategies to reduce: Increase research Better models Prevent/reduce pollution, reduce population, benign products

Matter: Forms, Structure, and Quality  Elements - building block of matter  Mixtures- various elements, compounds or both  Molecules- two or more atoms of same element  Compounds- two or more elements

Atoms Subatomic Particles  Protons  Neutrons  Electrons Atomic Characteristics  Atomic number  Ions  Atomic mass  Isotopes

Examples of Atoms Fig. 3-4 p. 48

Chemical Bonds  Chemical formulas- # of atoms in compound  Ionic bonds - oppositely charged Metal and nonmetal  Ionic bonds - oppositely charged Metal and nonmetal  Covalent bonds –valence Electron sharing (less water soluble than ionic bonds)  Covalent bonds –valence Electron sharing (less water soluble than ionic bonds)  Hydrogen bonds- H to Electronegative, weakest bond, occurs in organic and inorganic  Hydrogen bonds- H to Electronegative, weakest bond, occurs in organic and inorganic

Organic Compounds  Organic vs. inorganic compounds  Hydrocarbons- C and H  Chlorinated hydrocarbons – C, H, and Cl  Chlorofluorocarbons- C and Fl  Simple carbohydrates- C, H, O  Complex carbohydrates- polymer- 2 or more simple sugars  Proteins- monomers of amino acids

Genetic Material  Nucleic acids  Genes  Gene mutations  Chromosomes Fig. 3-6 p. 50

The Four States of Matter  Solid  Liquid  Gas  Plasma Fig. 3-7 p. 50

Matter Quality and Material Efficiency Fig. 3-8 p. 51  High-quality matter- near Earth’s surface  High-quality matter- near Earth’s surface  Low-quality matter Dilute, deep underground, ocean, atmosphere  Low-quality matter Dilute, deep underground, ocean, atmosphere  Material efficiency (resource productivity) Total amount of material needed to produce each unit of goods or services. 2-6% of matter used in developed countries provides useful goods.  Material efficiency (resource productivity) Total amount of material needed to produce each unit of goods or services. 2-6% of matter used in developed countries provides useful goods.

Energy: Forms  Kinetic energy  Potential energy Fig. 3-9 p. 52  Heat

Transfer of Heat Energy Fig p. 553 ConvectionConductionRadiation Heat from a stove burner causes atoms or molecules in the pan’s bottom to vibrate faster. The vibrating atoms or molecules then collide with nearby atoms or molecules, causing them to vibrate faster. Eventually, molecules or atoms in the pan’s handle are vibrating so fast it becomes too hot to touch. As the water boils, heat from the hot stove burner and pan radiate into the surrounding air, even though air conducts very little heat. Heating water in the bottom of a pan causes some of the water to vaporize into 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.

Energy: Quality Fig p. 53  High-quality energy  Low-quality energy

Physical and Chemical Changes Fig. In text p. 54

The Law of Conservation of Matter  Matter is not consumed  Matter only changes form  There is no “away”

Matter and Pollution  Chemical nature of pollutants  Concentration  Persistence  Degradable (nonpersistent) pollutants  Biodegradable pollutants  Slowly degradable (persistent) pollutants  Nondegradable pollutants

Nuclear Changes  Natural radioactive decay –measured by half life  Radioisotope – ex: Uranium 235 and 238, different half-lives =different energy Output or hazard  Natural radioactive decay –measured by half life  Radioisotope – ex: Uranium 235 and 238, different half-lives =different energy Output or hazard  Gamma rays –high energy Electromagnetic radiation  Gamma rays –high energy Electromagnetic radiation  Alpha particles  Beta particles  Half life ( See Table 3-2 p. 56)  Ionizing radiation –radiation from radioisotopes, harmful, often in normal Activities, can be in large doses (Chernobyl or 3 mile island  Ionizing radiation –radiation from radioisotopes, harmful, often in normal Activities, can be in large doses (Chernobyl or 3 mile island Fig p. 56

Nuclear Reactions Fission Fig p. 57 Fusion Fig p. 58

Laws Governing Energy Changes  Energy is neither created nor destroyed  Energy only changes form  You can’t get something for nothing First Law of Thermodynamics (Energy) ENERGY IN = ENERGY OUT

Laws Governing Energy Changes Second Law of Thermodynamics  In every transformation, some energy is converted to heat  You cannot break even in terms of energy quality

Connections: Matter and Energy Laws and Environmental Problems  High-throughput (waste) economy Fig p. 60; see Fig p. 61  Matter-recycling economy  Low-throughput economy