1. Science, Matter, Energy, and Systems
Chapter 2

2. Core Case Study: Carrying Out a Controlled Scientific Experiment
F. Herbert Bormann, Gene Likens, et al.: Hubbard Brook Experimental Forest in NH (U.S.)
Compared the loss of water and nutrients from an uncut forest (control site) with one that had been stripped (experimental site)

3. Figure 2.1
Controlled field experiment to measure the effects of deforestation on the loss of water and soil nutrients from a forest. V–notched dams were built into the impenetrable bedrock at the bottoms of several forested valleys (left) so that all water and nutrients flowing from each valley could be collected and measured for volume and mineral content. These measurements were recorded for the forested valley (left), which acted as the control site. Then all the trees in another valley (the experimental site) were cut (right) and the flows of water and soil nutrients from this experimental valley were measured for 3 years.
Stepped Art
Fig. 2-1, p. 28

4. 2-1 What Is Science?
Concept 2-1 Scientists collect data and develop theories, models, and laws about how nature works.

5. Science Is a Search for Order in Nature (1)
Identify a problem
Find out what is known about the problem
Ask a question to be investigated
Gather data
Hypothesize
Make testable predictions
Keep testing and making observations
Accept or reject the hypothesis

6. Science Is a Search for Order in Nature (2)
Important features of the scientific process
Curiosity
Skepticism
Peer review
Reproducibility
Openness to new ideas

7. Scientists Use Reasoning, Imagination, and Creativity to Learn How Nature Works
Important scientific tools
Inductive reasoning
Deductive reasoning
Scientists also use
Intuition
Imagination
Creativity

8. The Scientific Process
Identify a problem
The Scientific Process
Find out what is known
about the problem
(literature search)
Ask a question to be
investigated
Perform an experiment
to answer the question
and collect data
Analyze data
(check for patterns)
Scientific law
Well-accepted
pattern in data
Propose an hypothesis
to explain data
Use hypothesis to make
testable predictions
Figure 2.2
What scientists do. The essence of science is this process for testing ideas about how nature works. Scientists do not necessarily follow the exact order of steps shown here. For example, sometimes a scientist might start by formulating a hypothesis to answer the initial question and then run experiments to test the hypothesis.
Perform an experiment
to test predictions
Accept
hypothesis
Revise
hypothesis
Make testable
predictions
Test
predictions
Scientific theory
Well-tested and
widely accepted
hypothesis
Fig. 2-2, p. 30

9. Scientific Theories and Laws Are the Most Important Results of Science
Scientific hypothesis: a possible and testable explanation of what is observed in nature (edu. Guess)
Scientific theory
Supported by extensive evidence (tested many times)
Accepted by most scientists in a particular area
Explains
Scientific law, law of nature
Based on countless observations, tests
Describes

10. Read guest essay on global warming
The Scientific Consensus About Global Warming
John Harte

11. What is Global Warming?
Talking about the warming of the air atmosphere closest to ground.
More energy from the sun is kept at surface of earth than usual
Scientist are looking at some fundamental questions:
Is this actually occurring? (1⁰C increase in 10yrs)
Did humans cause this (cars, burning forests which add greenhouse gases like CO2 to atmo)
What could be result? (complex Q, complex A)

12. Economics/Politics/Ethics and Science
Any other possible causes?
Yes, changes in the Sun, Volcanoes, variation in earth’s orbit
Has this happened in the past, before humans?
Yes, many times
Ramifications and Blame?
Industries, Nations, Consumers
Scare Tactic?
Big business wants to paint warnings as a method of societal controlby government and shift the blame/concern

13. Figure 19.7
Some projected effects of global warming and the resulting changes in global climate, based on the extent of warming and the total atmospheric concentrations of greenhouse gases in parts per million. According to the IPCC, a warming of 2 C° (3.6 F°) over 2005 levels is unavoidable, and an increase of at least 3 C° (5.4 F°) is likely sometime during this century (Figure 19-B). (Data from 2007 Intergovernmental Panel on Climate Change Report and Nicolas Stern, The Economics of Climate Change: The Stern Report, Cambridge University Press, 2006)
Stepped Art
Fig. 19-7, p. 507

14. The Results of Science Can Be Tentative, Reliable, or Unreliable
Tentative science, frontier science (hypothesis)
Reliable science
(theory)
Unreliable science
(a theory based on false, misleading or no evidence, faith)

15. Environmental Science Has Some Limitations
Particular hypotheses, theories, or laws have a high probability of being true while not being absolute
Bias has to be minimized by scientists, for validity
Statistical methods may be used to estimate very large or very small numbers
Environmental phenomena involve many interacting variables and complex interactions, testability limitations
Scientific process is limited to the natural world (can not prove or disprove ethical or moral questions)

16. Science Focus: Statistics and Probability
Collect, organize, and interpret numerical data
Probability
The chance that something will happen or be valid

17. Animation: pH scale

18. 2-2 What Is Matter?
Concept 2-2 Matter consists of elements and compounds, which are in turn made up of atoms, and/or molecules.

19. Is everything made out of matter? Explain your answer.
What is matter?
Is everything made out of matter?
Explain your answer.

20. Matter
Has mass and takes up space

21. What is the difference between elements, compounds and mixtures?

22. Matter Consists of Elements and Compounds
Unique properties
Cannot be broken down chemically into other substances
Compounds
Two or more different elements chemically bonded together in fixed proportion
Mixtures: 2 or more elements, compounds or other mixtures physically mixed together

23. Elements you might consider important environmentally

24. Elements Important to the Study of Environmental Science

25. What is a compound? What is a mixture?
Orange Juice
Ketchup
Distilled Water
Steel
Water from a drinking fountain

26. What is the smallest amount of an element you can have that has all of its properties?

27. Model of a Carbon-12 Atom

28. Animation: Subatomic particles

29. Atoms, Ions, and Molecules Are the Building Blocks of Matter (1)
Atomic theory
Subatomic particles
Protons (p) with positive charge and neutrons (n) with no charge in nucleus (all the mass)
Negatively charged electrons (e) orbit the nucleus (almost no mass)

30. Numbers in chemistry Atomic number # of protons in each atom
Every element has a different # of protons
Mass number
Protons plus neutrons

31. Need a Periodic Table How many protons does Helium have? Argon?
What is the atomic number of Mercury, Nitrogen?
How many electrons does a stable atom of Oxygen have, how do you know?
What is the mass number of the most common form of Carbon, Lead

32. Animation: Atomic number, mass number

33. Atoms, Ions, and Molecules Are the Building Blocks of Matter (2)
Isotopes
Number of neutrons vary, properties same
Most common version founded by rounding atomic mass
Ions
Gain or lose electrons (exteme bonding)
Form ionic compounds

34. Need a periodic table
What is the most common isotope of Sulfur? Magnesium?
Determine how many electrons are lost or gained when atom of Fluorine or Boron is ionized
How are the most common ions of Oxygen and Lithium written

35. Animation: Isotopes

36. Animation: Ionic bonds

37. SO42- 2H20 Chemical Formulas Chemical formula
“Recipe” for 1 molecule of a chemical Compound
Letters
Numbers
Signs

38. Ions Important to the Study of Environmental Science

39. Why are ions important? Reactivity
Ions with an 1 extra electron or lacking one electron react more strongly
The stronger the reaction means more energy is released or absorbed
Greater effects

40. Loss of NO3− from a Deforested Watershed

41. Atoms, Ions, and Molecules Are the Building Blocks of Matter (3)
Two or more atoms of the same or different elements held together by chemical bonds

42. Compounds Important to the Study of Environmental Science

43. Animation: Carbon bonds

44. pH the acid test pH
Measure of acidity # of Hydrogen ions in a certain volume of a solution
Solution can be neutral , acidic, or basic
Defined by relative amounts of H+ and OH-
Something on either end of scale has a tendency to react strongly
Scale is exponential in amount, 10x for each step

45. Acid lab

46. Organic Compounds Are the Chemicals of Life
Organic compounds: contain 2 + Carbon atoms
1 exception: Methane CH4
Types
Hydrocarbons and chlorinated hydrocarbons
Simple carbohydrates
Macromolecules: complex organic molecules
Complex carbohydrates
Proteins
Nucleic acids
Lipids
Inorganic compounds: any other compound not organic

47. Arrange in terms of size
An Artery
Cell
Chromosomes
DNA Molecules
Electron
Genes
Nucleus (in terms of cells, not atoms)
One Atom
Proton

48. A human body contains trillions of cells, each with an identical set
of genes.
Each human cell (except for red
blood cells) contains a nucleus.
Each cell nucleus has an identical set
of chromosomes, which are found in
pairs.
A specific pair of chromosomes
contains one chromosome from each
parent.
Each chromosome contains a long
DNA molecule in the form of a coiled
double helix.
Figure 2.5
Relationships among cells, nuclei, chromosomes, DNA, and genes.
Genes are segments of DNA on
chromosomes that contain instructions
to make proteins—the building blocks
of life.
Stepped Art
Fig. 2-5, p. 38

49. Matter Comes to Life through Genes, Chromosomes, and Cells
Cells: fundamental units of life
Genes: sequences of nucleotides within the DNA , instructions for 1 trait
Chromosomes: composed of many genes

50. Matter Occurs in Various Physical Forms
Solid
Liquid
Gas (plasma)

51. Usefulness of matter High-quality matter Low-quality matter
Highly concentrated
Near surface
Great potential
Low-quality matter

52. 2-3 How Can Matter Change?
Concept 2-3 When matter undergoes a physical or chemical change, no atoms are created or destroyed (the law of conservation of matter).

53. Matter Undergoes Physical, Chemical, and Nuclear Changes
Physical change: chemical composition does not change (tear apart paper)
Chemical change, chemical reaction: permanent chemical composition change (burning wood to make smoke with CO2 )

54. Nuclear Change Nuclear change
Natural radioactive decay
Radioisotopes: unstable
Nuclear fission
Nuclear fusion
Difference between Nuclear and Chemical change
Chemical change alters bonds between atoms (electrons, molecules)
Nuclear change changes the nucleus of an atom (change # of protons, neutrons) (high energy)

55. Beta particle (electron) Radioactive decay
Radioactive isotope
Alpha particle
(helium-4 nucleus)
Gamma rays
Nuclear fission
Uranium-235
Energy
Fission
fragment
Neutron n
Nuclear fusion
Fuel
Proton
Neutron
Hydrogen-2
(deuterium nucleus)
Hydrogen-3
(tritium nucleus)
Reaction
conditions
100
million °C
Products
Helium-4 nucleus
Energy
Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Stepped Art
Fig. 2-7, p. 41

56. Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Fig. 2-7a, p. 41

57. Radioactive decay Alpha particle (helium-4 nucleus)
Radioactive isotope
Gamma rays
Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Beta particle (electron)
Fig. 2-7a, p. 41

58. Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Fig. 2-7b, p. 41

59. Nuclear fission Uranium-235 Fission fragment Energy n n Neutron n n
Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Energy
Fig. 2-7b, p. 41

60. Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Fig. 2-7c, p. 41

61. Nuclear fusion Reaction conditions Fuel Products Proton Neutron
Helium-4 nucleus
Hydrogen-2
(deuterium nucleus)
100
million °C
Energy
Figure 2.7
Types of nuclear changes: natural radioactive decay (top), nuclear fission (middle), and nuclear fusion (bottom).
Hydrogen-3
(tritium nucleus)
Neutron
Fig. 2-7c, p. 41

62. Animation: Half-life

63. Video: Nuclear energy

64. We Cannot Create or Destroy Matter
Law of conservation of matter
Matter consumption
Matter is converted from one form to another
Matter is never ‘lost’

65. Animation: Total energy remains constant

66. 2-4 What is Energy and How Can It Be Changed?
Concept 2-4A When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed (first law of thermodynamics).
Concept 2-4B Whenever energy is changed from one form to another, we end up with lower- quality or less usable energy than we started with (second law of thermodynamics).

67. Energy Comes in Many Forms
Kinetic energy
Energy of organized motion (most useful)
Heat (energy of unorganized motion (not as good)
Transferred by radiation, conduction, or convection
Electromagnetic radiation: KE transmitted as waves
Potential energy
Stored energy (GPE, EPE, chemical, nuclear)
Can be changed into kinetic energy

68. Energy emitted from sun (kcal/cm2/min)15 10
Energy emitted from sun (kcal/cm2/min) 5
Visible
Figure 2.8
Solar capital: the spectrum of electromagnetic radiation released by the sun consists mostly of visible light. See an animation based on this figure at CengageNOW.
Infrared
Ultraviolet
0.25 1 2
2.5 3
Wavelength (micrometers)
Fig. 2-8, p. 42

69. Active Figure: Visible light

70. Energy Changes Are Governed by Two Scientific Laws
First Law of Thermodynamics
Energy input always equals energy output
Second Law of Thermodynamics
Energy always goes from a more useful to a less useful form when it changes from one form to another
Energy efficiency or productivity

71. Some Types of Energy Are More Useful Than Others
High-quality energy
Low-quality energy
Determined by the capacity to do useful work

72. The Second Law of Thermodynamics in Living Systems

73. Active Figure: Energy flow

74. Do Personal Energy Audit Lab

75. 2-5 What Are Systems and How Do They Respond to Change?
Concept 2-5A Systems have inputs, flows, and outputs of matter and energy, and their behavior can be affected by feedback.
Concept 2-5B Life, human systems, and the earth’s life support systems must conform to the law of conservation of matter and the two laws of thermodynamics.

76. Systems Have Inputs, Flows, and Outputs
System: is a set of components that function and interact in some regular way
Parts of systems
Inputs from the environment
Flows, throughputs
Outputs to the environment

77. Inputs, Throughput, and Outputs of an Economic System

78. Animation: Economic types

79. Systems Respond to Change through Feedback Loops
Feedback: Any process which increases or decreases change to a system
Feedback stimulus: event or action which initiates the process of change(cycle or loop)
Examples (cutting down trees) (paying farmers not to farm marginal land)

80. Positive Feedback loop
Positive or amplified feedback loop: causes a system to change further in the same direction
Cutting trees in a valley event that started a loop concerning the increasing environmental health problems of the valley

81. Decreasing vegetation...
...which causes
more vegetation
to die.
...leads to
erosion and
nutrient loss...
Figure 2.11
Positive feedback loop. Decreasing vegetation in a valley causes increasing erosion and nutrient losses, which in turn causes more vegetation to die, which allows for more erosion and nutrient losses. The system receives feedback that continues the process of deforestation.
Fig. 2-11, p. 45

82. Negative feedback loop
Negative, or corrective, feedback loop: causes a change in the opposite direction to which it was moving
Automatic thermostats in homes
Increased recycling of aluminum, in terms of mining

83. Temperature reaches desired setting and furnace goes off
House warms
Temperature reaches desired setting
and furnace goes off
Furnace on
Figure 2.12
Negative feedback loop. When a house being heated by a furnace gets to a certain temperature, its thermostat is set to turn off the furnace, and the house begins to cool instead of continuing to get warmer. When the house temperature drops below the set point, this information is fed back, and the furnace is turned on and runs until the desired temperature is reached. The system receives feedback that reverses the process of heating or cooling.
House cools
Temperature drops below desired setting
and furnace goes on
Fig. 2-12, p. 45

84. Animation: Feedback control of temperature

85. What kind of feedback loop occurs:
Enforcement of no cell phones in class room on student achievement, class discipline?
Commitment to recycling more at lunch on keeping the lunchroom clean,
Commitment to quotas on the number of tuna that can be caught during a season to the health of the tuna population
Lemmings

86. Time Delays Can Allow a System to Reach a Tipping Point
Time delays vary
Between the input of a feedback stimulus and the response to it by the system
Tipping point, threshold level
Causes a shift in the behavior of a system
Land unable to support trees, crops
Once crossed, takes a lot of time, change in conditions to revert

87. Haiti and deforestation

88. System Effects Can Be Amplified through Synergy
Synergistic interaction, synergy
2 or more processes interact so combined effect is greater than either can produce separately
Helpful (1 person, group working on a cause)
Harmful
E.g., Smoking and inhaling asbestos particles and risk of cancer
10 fold, 5 fold, combined 50 fold

89. Human Activities Can Have Unintended Harmful Results
Deforested areas turning to desert (Haiti)
Associated with Global Warming
Coral reefs dying (Belize, Australia)
Glaciers melting (US, Europe)
Sea levels rising (global)

90. Connected to the information presented in this chapter
Your Questions?
Connected to the information presented in this chapter

91. UN Project Questions for the chapter
What are the major forms of energy used to fuel the economy, society in your country
Where do the major Sources of the fuel come from, Are they derived from inside the country?
Has the government signed the Kyoto agreements? If not, can you come up with a reason?
Are there any effects of global warming evident connected to the country?