Science, Systems, Matter, and Energy G. Tyler Miller’s Living in the Environment 14 th Edition Chapter 3 G. Tyler Miller’s Living in the Environment 14 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. 33

Models and Behavior of Systems  Inputs  Flows (throughputs)  Stores (storage areas)  Outputs

System Regulation  Positive Feedback  Negative Feedback  Time Delay  Synergy

Feedback loops: Negative feedback Feedback loop = a circular process whereby a system’s output serves as input to that same system In a negative feedback loop, output acts as input that moves the system in the opposite direction. This compensation stabilizes the system.

LE 3-1a Negative feedback Too hot Too cold Brain (control center) Seek shade Sweat Wear more clothes Shiver Body cools Body warms

Feedback loops: Positive feedback In a positive feedback loop, output acts as input that moves the system further in the same direction. This magnification of effects destabilizes the system.

LE 3-1b Small gully Vegetation helps prevent erosion Cleared patches of vegetation More exposed soil Banks cleared of vegetation are vulnerable to erosion Running water expands gully and erodes surrounding soil Erosion continues Positive feedback

Matter: Forms, Structure, and Quality  Elements  Compounds  Molecules  Ions  Atoms

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

Examples of Isotopes Fig. 3-5 p. 40

pH  Measures acidity or alkalinity of water samples  Scale 0 – 14  Acids: 0 – 6.9  Neutral 7.0  Alkaline (Basic) 7.1 – 14  Measures acidity or alkalinity of water samples  Scale 0 – 14  Acids: 0 – 6.9  Neutral 7.0  Alkaline (Basic) 7.1 – 14 NaOH (sodium hydroxide) Ammonia Soft soap Seawater Pure water Normal rainwater Acid rain Stomach acid Lemon juice Extreme acid rain Car battery acid HCl (hydrochloric acid) Acidic Neutral Basic

Chemical Bonds  Chemical formulas  Ionic bonds  Covalent bonds

Organic Compounds  Organic vs. inorganic compounds  Hydrocarbons  Chlorinated hydrocarbons  Nucleic acids  Simple carbohydrates  Complex carbohydrates  Proteins

Genetic Material  Nucleic acids  Genes  Genomes  Chromosomes Compare Fig. 3-7 p. 42

The Four States of Matter  Solid  Liquid  Gas  Plasma

Matter Quality and Material Efficiency Fig. 3-8 p. 43  High-quality matter  Low-quality matter  Material efficiency (resource productivity)

Energy  Definition: Capacity to do “work” and transfer heat  Types:  Kinetic  Potential  Radiation: Energy & Wavelength  Definition: Capacity to do “work” and transfer heat  Types:  Kinetic  Potential  Radiation: Energy & Wavelength

Electromagnetic Spectrum Fig. 3-9 p. 44

Transfer of Heat Energy Fig p. 45 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  High-quality energy  Low-quality energy Fig p.46

Changes in Matter  Physical  Chemical  Physical  Chemical

Chemical Changes or Reactions Fig. In text p. 47

The Law of Conservation of Matter  Matter is not destroyed  Matter only changes form  There is no “throw 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  Radioactive isotopes (radioisotopes)  Gamma rays  Alpha particles  Beta particles  Half life ( See Table 3-2 p. 49)  Ionizing radiation

Half-life Fig. 3-13, p. 49

Nuclear Reactions Fission Fig p. 50 Fusion Fig p. 50

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

Laws of Thermodynamics First Law: (CHANGE) Energy is neither created nor destroyed but may be converted from one form to another. NO FREE LUNCHES! Second Law: (LOSS) In any energy conversion, you will end up with less usable energy than you started with. YOU CAN’T BREAK EVEN!

Entropy: Energy Changes in Organisms Systems will go spontaneously in one direction only, which is toward increasing entropy..

Connections: Matter and Energy Laws and Environmental Problems  High-throughput (waste) economy  Matter-recycling economy  Low-throughput economy

Environmental Solutions: Low- Throughput Economy  Learning from Nature Fig p. 53