Science, Systems, Matter, and Energy Chapter 3 APES Ms. Miller Chapter 3 APES Ms. Miller

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: (facts collected)  Scientific (natural) laws: Principle that describes the behavior of something in nature  Scientific (natural) laws: Principle that describes the behavior of something in nature  Consensus science: sound science—data, theories and laws widely accepted by scientists  Scientific theories: set of related hypothesis that have tested and confirmed many times  Scientific hypotheses: (possible explanations)  Frontier science: has not been widely tested; controversial 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—(from environment) Using humans as an example….. Energy Matter Information  Inputs—(from environment) Using humans as an example….. Energy Matter Information

 Flows (throughputs)—within the system at certain rates

 Stores (storage areas)—inputs stored for certain amount of time

 Outputs—go to environment Heat Ideas and Actions Waste and Pollution

System Regulation  Positive Feedback Loop— causes system to change but moves in same direction

 Negative Feedback Loop—causes system to change in opposite direction

 Time Delay—period between input of stimulus and response to it

 Synergy—when two or more processes interact so that the combined effect is greater than the sum of their separate effects

Matter: Forms, Structure, and Quality  Elements— pure substance; one type of atom  Compounds— two or more types of elements held by chemical bonds  Molecules— combination of two or more atoms of the same or different element held by chemical bonds  Ions— an electrically charged atom  Atoms— basic building block of matter

Atoms Subatomic Particles  Protons- positive charge; in nucleus  Neutrons- no charge; in nucleus  Electrons- negative charge; in shell Atomic Characteristics  Atomic number= Number of protons  Ions-- #protons not equal to #electrons  Atomic mass= #protons + # neutrons  Isotopes— same elemental atom but different number of neutrons

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

Chemical Bonds  Chemical formulas— number of atoms or ions of each type in a compound

 Covalent bonds—the sharing of electrons  Ionic bonds—the transfer of electrons

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— definite shape and volume

 Liquid— definite volume but takes shape of container (reservoir)

 Gas— does not have definite shape or volume; can be compressed many times

 Plasma— most abundant form of matter in universe; is a high energy mixture of positive ions and negative electrons

Matter Quality and Material Efficiency Fig. 3-8 p. 43  High-quality matter (great potential for use as resource)  High-quality matter (great potential for use as resource)  Low-quality matter (little potential for use as a resource)  Low-quality matter (little potential for use as a resource)  Material efficiency (resource productivity) Is the total amount of material needed to produce each unit of goods or services  Material efficiency (resource productivity) Is the total amount of material needed to produce each unit of goods or services

Energy  Definition: Capacity to do “work” and transfer heat  Types:  Kinetic- energy possessed by matter due to motion  Potential- stored energy which has potential for use  Radiation: Energy & Wavelength  Definition: Capacity to do “work” and transfer heat  Types:  Kinetic- energy possessed by matter due to motion  Potential- stored energy which has potential for use  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 (concentrated energy)  High-quality energy (concentrated energy)  Low-quality energy (dispersed energy)  Low-quality energy (dispersed energy) Fig p.46

Changes in Matter  Physical— chemical composition not changed; molecules altered by being in different patterns

 Chemical—change in chemical composition

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

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