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Environmental Science
A Study of Interrelationships
Thirteenth Edition

Enger & Smith

Chapter 4
Interrelated Scientific P...
4.1 The Nature of Science
 Science is a process
• used to solve problems/develop an understanding of
nature
• that involv...
Scientific Method
 Scientific method
• way of gaining information (facts) about the world by
forming possible solutions t...
Components of Scientific Method
 Observation
 Asking questions
 Testing hypothesis
 Openness to new info
 Willingness...
Observation and Asking Questions
 Observation occurs when we use our senses or
extensions of our senses to Record an even...
Constructing a hypothesis
 Hypothesis
• testable statement that provides a possible answer to
a question, or an explanati...
Test a Hypothesis
 An experiment
• re-creation of an event that enables an investigator to
support or reject a hypothesis...
Fig. 1-15-2

Environmental Science
A Study of Interrelationships
Thirteenth Edition

Enger & Smith

Copyright © The McGraw...
Elements of the Scientific Method
• A theory
– is a widely accepted, plausible generalization about
fundamental scientific...
Elements of the Scientific Method
 Communication
• publication of articles
in scientific journals
• opportunity to critic...
Elements of the Scientific Method

Scientific ideas undergo
constant reevaluation, criticism,
and modification.
4.2 Limitations of Science
 Different types of questions science cannot answer
• Evaluate beauty/art
• Limited to natural...
4.3 Pseudoscience
 Pseudoscience
• deceptive practice that uses the appearance or
language of science
• To convince, conf...
Pseudoscience


Evaluation of a claim
1.
2.
3.
4.
5.

Are the ‘facts’ true as stated?
Is there an alternative explanation...
In Class Assignment
 Lab Report
4.4 The Structure of Matter
 Matter is anything that has mass and takes up
space.
• The kinetic molecular theory
– descri...
Atomic Structure
 The atom is the fundamental unit of matter.
 There are 92 types of atoms found in nature, with
each be...
Atomic Structure

Diagrammatic oxygen atom. Oxygen is an Element
Atomic Structure
 All atoms of the same element have the same
number of protons and electrons
• but may vary in the numbe...
Atomic Structure

Isotopes of hydrogen
The Molecular Nature of Matter
 Molecules are atoms bonded together into
stable units.
• Ions are electrically charged pa...
NaCl – Table Salt

Attracted to each other!
The Molecular Nature of Matter
 Compounds are formed when two or more
atoms or ions bind to one another.
• Water (H2O)
• ...
Molecular Nature of Matter
 Mixtures are variable combinations of atoms,
ions, or molecules.
• Honey (several sugars + wa...
A Word About Water
 ¾ of the Earth’s
surface is covered
with water.
 Water determines the
weather and climate
of a regio...
States of Matter
Water can exist in 3 phases: solid, liquid, and
gas.
A Word About Water
 Water molecules with positive and negative
ends.
 Unlike charges attract and water molecules tend
to...
Water Molecule

Molecules stick together well
Inorganic and Organic Matter
 Organic matter
• molecules that contain carbon atoms
• usually bonded to form rings or chai...
Figure 04_07
Chemical Reactions
 Chemical bonds
• attractive forces between atoms resulting from the
interaction of their electrons
• ...
Chemical Reactions
In exothermic reactions,
chemical bonds in the new compounds
contain less chemical energy than the prev...
Chemical reactions
 In endothermic reactions, the newly formed chemical
bonds contain more energy than the previous compo...
Reactantsproducts
 Exothermic
• Release energy (heat)

 Endothermic
• Need energy
Chemical Reactions in Living Things
Photosynthesis
• process used by plants to convert inorganic material
into organic ma...
Chemical Reactions in Living Things

Photosynthesis
Chemical Reactions in Living Things
 Respiration
• process that uses oxygen to break down large,
organic molecules into s...
Chemical Reactions in Living Things

Respiration
Photosynthesis vs Cellular Respiration
 Photosynthesis
• In plants only
– reactants (water, CO2, light)
– products (O2, c...
Video

 http://www.teachersdomain.org/asset/tdc02_vid_pho
4.5 Energy Principles
 Energy--ability to
perform work.
 Work is done when
an object is moved
over a distance.
• Kinetic...
Potential Energy Comes in
Many Forms
Kinetic and Potential Energy
 Nose-basher Pendulum
 http://www.youtube.com/watch?v=fR-Y9cx0XSM
States of Matter
 The state of matter depends on the amount of
energy present.
• The amount of kinetic energy contained i...
4.5 Energy Principles

States of matter
First Laws of Thermodynamics
 Energy can be converted from one form to another,
but the amount remains constant.
• 1st La...
Discussion
 Handout
Second Laws of Thermodynamics
• 2nd Law: When converting energy from one form to
another, some of the useful energy is los...
First and Second Laws of Thermodynamics

Second law of thermodynamics
4.6 Environmental Implications of Energy
Flow
 All living things and machines release heat
• Heat is dissipated into the ...
4.6 Environmental Implications of Energy
Flow
 Some forms of energy are more useful than others.
 Low quality: Cannot be...
4.6 Environmental Implications of Energy
Flow
 We can sometimes figure new ways to convert lowquality energy to high-qual...
Biological Systems and Thermodynamics
 All organisms, including humans, are in the
process of converting high-quality ene...
Pollution and Thermodynamics
 If each person on Earth used less energy,
• there would be less waste heat
• Less pollution...
Summary
 Science is a method of gathering and organizing
information.
 A hypothesis is a logical prediction about how th...
Summary
 The fundamental unit of matter is the atom,
which is made up of protons and neutrons in the
nucleus surrounded b...
Summary
 Matter can occur in three states: solid, liquid,
and gas.
 Kinetic energy is the energy contained by
moving obj...
Assignment links

 http://americanpolicy.org/2002/03/29/there-is-no-glob

http://www.ucsusa.org/food_and_agriculture/our-...
How chemistry and the environment mix lecture 2
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How chemistry and the environment mix lecture 2

  1. 1. Environmental Science A Study of Interrelationships Thirteenth Edition Enger & Smith Chapter 4 Interrelated Scientific Principles: Matter, Energy, and Environment Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  2. 2. 4.1 The Nature of Science  Science is a process • used to solve problems/develop an understanding of nature • that involves testing possible answers • Scientific method
  3. 3. Scientific Method  Scientific method • way of gaining information (facts) about the world by forming possible solutions to questions • followed by rigorous testing to determine if the proposed solutions are valid.  Presumptions • Specific causes exist for observed events. • These causes can be identified.
  4. 4. Components of Scientific Method  Observation  Asking questions  Testing hypothesis  Openness to new info  Willingness to submit ideas to criticism
  5. 5. Observation and Asking Questions  Observation occurs when we use our senses or extensions of our senses to Record an event.  Observations often lead to additional questions about the observations. • Robin and berries….Why?  Exploring other sources of knowledge • What have other people reported?
  6. 6. Constructing a hypothesis  Hypothesis • testable statement that provides a possible answer to a question, or an explanation for an observation. – Logical – Account for all relevant information currently available – Allow prediction of related future events – Be Testable – “If I drop my keys, they will fall”
  7. 7. Test a Hypothesis  An experiment • re-creation of an event that enables an investigator to support or reject a hypothesis. • A controlled experiment divides the experiment into two groups (experimental and control) that differ by only one variable.  Reproducibility • experiment must be able to be repeated • By independent investigators to ensure a lack of bias.
  8. 8. Fig. 1-15-2 Environmental Science A Study of Interrelationships Thirteenth Edition Enger & Smith Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
  9. 9. Elements of the Scientific Method • A theory – is a widely accepted, plausible generalization about fundamental scientific concepts – Broad concept – Supported by multiple hypotheses, multiple experiments – Years of data • A scientific law – is a uniform or constant fact of nature that describes what happens in nature – Law of gravity
  10. 10. Elements of the Scientific Method  Communication • publication of articles in scientific journals • opportunity to criticize, make suggestions, or agree
  11. 11. Elements of the Scientific Method Scientific ideas undergo constant reevaluation, criticism, and modification.
  12. 12. 4.2 Limitations of Science  Different types of questions science cannot answer • Evaluate beauty/art • Limited to natural world  Scientists have moral and ethical questions • Differentiate between data collected during an investigation • and Opinions of what the data mean  Scientific knowledge can be used to support both valid and invalid conclusions.
  13. 13. 4.3 Pseudoscience  Pseudoscience • deceptive practice that uses the appearance or language of science • To convince, confuse, or mislead people into thinking that something has scientific validity when it does not
  14. 14. Pseudoscience  Evaluation of a claim 1. 2. 3. 4. 5. Are the ‘facts’ true as stated? Is there an alternative explanation? Is the claim falsifiable? Have claims been tested? Do claims require unreasonable changes in accepted ideas?
  15. 15. In Class Assignment  Lab Report
  16. 16. 4.4 The Structure of Matter  Matter is anything that has mass and takes up space. • The kinetic molecular theory – describes the structure and activity of matter. – all matter is made up of one or more kinds of smaller subunits (atoms) that are in constant motion.
  17. 17. Atomic Structure  The atom is the fundamental unit of matter.  There are 92 types of atoms found in nature, with each being composed of: • Protons (Positively charged) • Neutrons (Neutral) • Electrons (Negatively charged)  Each kind of atom forms a specific type of matter known as an element.
  18. 18. Atomic Structure Diagrammatic oxygen atom. Oxygen is an Element
  19. 19. Atomic Structure  All atoms of the same element have the same number of protons and electrons • but may vary in the number of neutrons. • Isotopes are atoms of the same element that differ from one another in the number of neutrons they contain.
  20. 20. Atomic Structure Isotopes of hydrogen
  21. 21. The Molecular Nature of Matter  Molecules are atoms bonded together into stable units. • Ions are electrically charged particles. – Atoms that lose electrons = positively charged – Atoms that gain electrons = negatively charged
  22. 22. NaCl – Table Salt Attracted to each other!
  23. 23. The Molecular Nature of Matter  Compounds are formed when two or more atoms or ions bind to one another. • Water (H2O) • Table sugar (C6H12O6) • Salt (NaCl)
  24. 24. Molecular Nature of Matter  Mixtures are variable combinations of atoms, ions, or molecules. • Honey (several sugars + water) • Concrete (cement, sand, and gravel) • Air (various gases including nitrogen and oxygen)
  25. 25. A Word About Water  ¾ of the Earth’s surface is covered with water.  Water determines the weather and climate of a region  The most common molecule found in living things is water.
  26. 26. States of Matter Water can exist in 3 phases: solid, liquid, and gas.
  27. 27. A Word About Water  Water molecules with positive and negative ends.  Unlike charges attract and water molecules tend to stick together.  Much energy is needed to separate water molecules and convert liquid water to vapor.  Water is the universal solvent. Most things dissolve to some degree in it.
  28. 28. Water Molecule Molecules stick together well
  29. 29. Inorganic and Organic Matter  Organic matter • molecules that contain carbon atoms • usually bonded to form rings or chains • All living things contain molecules of organic compounds – chemical bonds in organic molecules contain a large amount of chemical energy – released when the bonds are broken
  30. 30. Figure 04_07
  31. 31. Chemical Reactions  Chemical bonds • attractive forces between atoms resulting from the interaction of their electrons • Breaking and forming of chemical bonds to rearrange atoms into new molecules • When chemical bonds are formed or broken, a chemical reaction occurs. – exothermic reactions – endothermic reactions
  32. 32. Chemical Reactions In exothermic reactions, chemical bonds in the new compounds contain less chemical energy than the previous compounds. Reactants  products
  33. 33. Chemical reactions  In endothermic reactions, the newly formed chemical bonds contain more energy than the previous compounds.  Energy is absorbed from surroundings (cold pack) Ammonium Nitrate + water + energy Oxide Ammonium +Nitric
  34. 34. Reactantsproducts  Exothermic • Release energy (heat)  Endothermic • Need energy
  35. 35. Chemical Reactions in Living Things Photosynthesis • process used by plants to convert inorganic material into organic material using light. • Carbon dioxide + water (in the presence of sunlight) produces glucose + oxygen. • 6CO2 + 6H2O + Light C6H12O6 + 6O2 Reactants  products
  36. 36. Chemical Reactions in Living Things Photosynthesis
  37. 37. Chemical Reactions in Living Things  Respiration • process that uses oxygen to break down large, organic molecules into smaller inorganic molecules (releases energy organisms can use). • Glucose + oxygen produces carbon dioxide + water + energy • C6H12O6 + 6O2  6CO2 + 6H2O + energy
  38. 38. Chemical Reactions in Living Things Respiration
  39. 39. Photosynthesis vs Cellular Respiration  Photosynthesis • In plants only – reactants (water, CO2, light) – products (O2, carbohydrates) – endothermic  Cellular Respiration • In plants and animals – reactants (O2, carbohydrates) – products (water, CO2, energy) – exothermic
  40. 40. Video  http://www.teachersdomain.org/asset/tdc02_vid_pho
  41. 41. 4.5 Energy Principles  Energy--ability to perform work.  Work is done when an object is moved over a distance. • Kinetic energy-energy contained by moving objects. • Potential energy-energy waiting to be released
  42. 42. Potential Energy Comes in Many Forms
  43. 43. Kinetic and Potential Energy  Nose-basher Pendulum  http://www.youtube.com/watch?v=fR-Y9cx0XSM
  44. 44. States of Matter  The state of matter depends on the amount of energy present. • The amount of kinetic energy contained in a molecule determines how rapidly it moves. – Solids: particles have low energy and vibrate in place very close to one another. – Liquids: More energy; molecules are farther apart from one another. – Gases: Molecular particles move very rapidly and are very far apart.
  45. 45. 4.5 Energy Principles States of matter
  46. 46. First Laws of Thermodynamics  Energy can be converted from one form to another, but the amount remains constant. • 1st Law: Energy cannot be created or destroyed; it can only be changed from one form to another.
  47. 47. Discussion  Handout
  48. 48. Second Laws of Thermodynamics • 2nd Law: When converting energy from one form to another, some of the useful energy is lost • Example: No engine can exclusively convert heat to work – Entropy is the energy that cannot be used to do useful work. – Every isolated system tends toward disorder
  49. 49. First and Second Laws of Thermodynamics Second law of thermodynamics
  50. 50. 4.6 Environmental Implications of Energy Flow  All living things and machines release heat • Heat is dissipated into the environment.  Orderly arrangements of matter tend to become disordered. • …things break down, wear out….release heat  The process of becoming disordered coincides with the constant flow of energy toward low quality heat
  51. 51. 4.6 Environmental Implications of Energy Flow  Some forms of energy are more useful than others.  Low quality: Cannot be used to perform useful work  Low-quality energy still has significance in the world. • The distribution of heat energy in the ocean moderates the temperature of coastal climates. • It contributes to weather patterns and causes ocean currents that are important in many ways.
  52. 52. 4.6 Environmental Implications of Energy Flow  We can sometimes figure new ways to convert lowquality energy to high-quality energy. • Improvements in wind turbines and photovoltaic cells allow us to convert low-quality light and wind to electricity.
  53. 53. Biological Systems and Thermodynamics  All organisms, including humans, are in the process of converting high-quality energy into low-quality energy.  When chemical-bond energy in food is converted into the energy needed to move, grow, or respond, waste heat is produced.
  54. 54. Pollution and Thermodynamics  If each person on Earth used less energy, • there would be less waste heat • Less pollution that result from energy conversion – Emissions from power plants.  The amount of energy in the universe is limited, and only a small portion of that energy is highquality.
  55. 55. Summary  Science is a method of gathering and organizing information.  A hypothesis is a logical prediction about how things work that must account for all the known information and be testable.  If a hypothesis is continually supported by the addition of new facts, it may be incorporated into a theory.  A law is a broad statement that describes what happens in nature.
  56. 56. Summary  The fundamental unit of matter is the atom, which is made up of protons and neutrons in the nucleus surrounded by a cloud of moving electrons.  Chemical bonds are physical attractions between atoms resulting from the interaction of their electrons.  When chemical bonds are broken or formed, a chemical reaction occurs, and the amount of energy within the chemical bonds is changed.
  57. 57. Summary  Matter can occur in three states: solid, liquid, and gas.  Kinetic energy is the energy contained by moving objects; potential energy is the energy an object has because of its position.  The first law of thermodynamics states that the amount of energy in the universe is constant.  The second law of thermodynamics states that when energy is converted from one form to another, some of the useful energy is lost.
  58. 58. Assignment links  http://americanpolicy.org/2002/03/29/there-is-no-glob http://www.ucsusa.org/food_and_agriculture/our-failin http://zapatopi.net/treeoctopus/

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