Living in the Environment A Quick Review of Basic Concepts in Science, Systems, Matter, and Energy G. Tyler Miller’s Living in the Environment 14th 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 Energy: forms, quality, and how it changes; laws of energy Nuclear changes and radioactivity

The Nature of Science Science is an attempt to discover order in the natural world and use the knowledge to describe what is likely to happen in nature GOAL: to increase our understanding of our world Based upon the scientific process

The Nature of Science Attempt to solve a problem Follow the process and repeat!

Three critical components to any “good science” The Nature of Science Three critical components to any “good science” Skepticism: Do not believe what you see until verified Reproducible: data and results should be able to be done over and over Peer Review: other scientists must review work (vs. “Junk science”)

Science, and Critical Thinking 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 accepted patterns In data become scientific laws Scientific data Scientific hypotheses: IF…THEN…BECAUSE… Scientific (natural) laws Scientific theories Frontier science Junk Science Fig. 3-2 p. 33

The Nature of Science Scientists can do 2 major things: Attempts to disprove things Can establish that a particular model, theory, or law has a high degree of certainty of being true. NOT ABSOLUTELY TRUE Scientists should not say “Cigarettes Cause Cancer” but can say “There is overwhelming evidence (SUPPORTS/ DOES NOT SUPPORT!) from thousands of studies that indicate a relationship between cigarette usage and lung cancer”

Models and Behaviors of Systems Any action in a complex system has multiple, unintended, and often unpredictable effects. Regulation of systems Positive and Negative Feedback loops Examples??? Synergy

Negative feedback loop

Positive feedback loop

Matter: Forms, Structure, and Quality What do these terms mean? Elements Compounds Atoms Ions Molecules

Atoms Subatomic Particles Protons Neutrons Electrons Atomic Characteristics Isotopes Hydrogen 1, 2 and 3 Atomic number Carbon # 6, Uranium #92 Atomic mass Uranium 235 Ion Lost or gained e-

Examples of Isotopes Fig. 3-5 p. 40

Acids: 0 – 6.9 Neutral 7.0 Alkaline (Basic) 7.1 – 14 pH Measures acidity or alkalinity of water samples Scale 0 – 14 Acids: 0 – 6.9 Neutral 7.0 Alkaline (Basic) 7.1 – 14 Testing your Soil pH for growth of plants video

Chemical Bonds - Animations Chemical formulas Ionic bonds Covalent bonds

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

High quality (more concentrated) vs. Low Quality Matter (more diluted) Matter Quality – how useful it is as a resource; based on availability and concentration High quality (more concentrated) vs. Low Quality Matter (more diluted) Material Efficiency (Resource productivity) – total amount of material needed to produce each good Fig. 3-8 p. 43

Energy Capacity to do “work” and transfer heat Types: Kinetic (Heat, electricity) Potential (stored) Radiation: Energy & Wavelength

Electromagnetic Spectrum Some energy travels in waves at the speed of light Ionizing Radiation – Enough energy to knock e- from other atoms, changing them to positively charged particles; damaging to cells Fig. 3-9 p. 44

Transfer of Heat Energy Convection Conduction Radiation 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. Heat: total kinetic energy of all moving atoms in a substance.

Energy: Quality (ability to do work) High-quality energy Low-quality energy Fig. 3-12 p.46

Changes in Matter Physical: composition unchanged (water and steam) Chemical: change in the composition of elements or compounds.

Chemical 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 – severity based on chemical nature, concentration and persistence. Concentration (ppm – 1 part pollutant per million parts gas, water etc; ppb, ppt) Persistence Degradable (non-persistent) Biodegradable - bacteria Slowly degradable (persistent) pollutants – DDT, plastics Nondegradable (persistent) – lead, mercury arsenic

Great Pacific Garbage Patch Lead Poisoning and Gold Mining

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

Radioactive Isotopes Examples: Iodine - 131 (131I): injected into humans to study the function of the thyroid gland. Can be seen through special equipment that picks up on the radiation energy given off by this isotope as it travels through the body. Carbon-14 (14C): used to treat brain tumors and track the ages of trees and fossils.

Nuclear Reactions Fission Fusion Fig. 3-15 p. 50 Fig. 3-16 p. 50

Half life Problems!

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

Second Law of Thermodynamics In every transformation, some energy is converted to heat (lost) You cannot break even in terms of energy quality