TEXT READINGS: Chapter 1, Chap 3, Chap 4

In both of these topics 2 and 3, do not be overly concerned about the large amounts of text material that have been assigned, read mostly for an overview in most cases. Try to be more specific to answer the questions both here and eventually on an exam. Many times in the course I will refer you back to these pages as necessary. The same thinking should be applied to looking at some of the internet sites, use them to get some additional understanding, but do not feel that you have to absolutely understand every last item. And, it is not necessary that you look at every site that I have found, I would hope that you would look at some of the notes and graphics that I have made and would usually talk about in lecture. These are denoted as "ProfONotes". I will not test your "memory" of these topics, but will be looking for demonstration of an understanding of the basics with full resources available.


Molecule or Report of the Week: Chemical Element Report.

Choose ONE element except H, O, or C.
First look at the Discussion board to find an element different from those already posted.
Use the all THREE internet sites or the text book to find as much as possible of the following information:

Name, symbol, number of protons, neutrons, electrons, Bohr Model placement of electrons ( or statement of the number of electrons in each energy level - see p. 88), Wave Mechanical Model (Electron Configuration) placement of electrons.
Give several physical properties of the element.
Give some reactions (chemical properties), such as reaction with water and air.

Natural source or ore (maybe the name of the rock or mineral, or compound or mixture it is found in) of the element including its natural state (solid, liquid, or gas).
Who discovered the element and when?
What method is used to produce the pure element?
What are some products and compounds made with the element
What are the uses of the element?
Is the element useful for life or a poison?
Any other interesting details. 

Write a short report to summarize your findings. Put this into your own words and do not just copy and paste some of the info.

All parts of the question must be answered for full credit.

Resources:

Three Periodic Tables among many on the web. Use all of them as the info is presented in slightly different forms on each.

WebElements- Scholar Edition - Data, description, uses, historical, be sure to click some of the items in the Right side menu.  Such as history, reactions, electron shell properties - this will give the Bohr diagram and wave mechanical placement (electron configuration) of the electrons.

Periodic Table at Los Alamos Lab - contains information about each element.

Periodic Table - gives a graphic picture of the Bohr Diagram of each element. First select an element, then at the top of the frame, click on Atomic Structure to see the Bohr Diagram.

Elements for Life - click on an element.
Role of Element in Life -

It is also OK to use Wikipedia.org. They probably have more than what is in the periodic tables above. Just type in the element name in the search box. Pick out somethings that interest you and report on them. Still complete the items on the left.


Part II:  Content Questions A

Do the assigned question above.

After you have written your answer in a word processor, then go to the Discussion Board to post it.

1. Physical States of Matter - solid, liquid, gas

States of Matter  Text: p.1-7  

 

Use Hydrologic Cycle with water as examples  Text p. 282-3

ProfONotes: Water Cycle

NOTES: The hydrologic cycle is a way of thinking about how water circulates from lakes, oceans (liquid state) to the atmosphere (gas state) and back to the surface of the earth as precipitation (rain-liquid, snow, ice-solid ).  Water is also used to illustrate the three state of matter.

QUES. 1: What other terms can you think of that relate to changes of "state" or form for water such as transpiration (change of water to vapor or gas state from the leaves of plants), evaporation, condensation, etc.? Give examples and definitions.

Can you think of any other examples using other substances (besides water) of the three states of matter.
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2. Classification - Forms of Matter

 A. Mixtures - Homogeneous vs. Heterogeneous;
      Solids vs. Solutions

Text p. 7-9

ProfONotes: Mixtures
ProfONotes: Matter
ProfONotes: Compounds

 B. Pure Substances - Elements and Compounds (Graphite, Diamond, sodium chloride crystals)

  Text p. 9-10

ProfONotes:  Elements

Text p. 10-13

ProfONotes:  Atoms

 D. Acids, Bases, and Salts; Organic Molecules (very brief look ahead)

 Text p. 180-4

QUES. 2: Define the above terms mixtures; pure substances; atoms and molecules; acids, bases, and salts; and give examples. See 2A-d on the outline. Be sure to explain and contrast homogeneous vs. heterogeneous; elements vs. compounds; atoms vs. molecules.

Various students could answer this partially and others could complete it, expand or give some other examples. Each student should do two things.

One person can use the text p. 16 to explain what the pictures mean in Figs. 1.3, 1.6, 1.8, 1.10.

Text p. 7-13

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 A. Physical Properties and Changes

 Text p. 3-6
ProfONotes: Physical Properties

NOTES: The main idea is that in physical changes, the atom, compound, or individual molecules remain intact through all of the changes. The same atom or molecule is present at the beginning and the end of the physical change. The water molecule H2O is always present in ice, water, and water vapor.  In the graphic “dry” ice is a solid form of carbon dioxide.  Usually you think of carbon dioxide in the form of a gas.

 B. Chemical Changes and Properties

 Text p. 3-6

NOTES:  In a chemical change, the basic molecular structure is altered - bonds are broken in some molecules and the atoms are rearranged to form new bonds and new and different compounds and molecules are present at the end of the reaction. Electrons are involved in the formation and breaking of the bonds between atoms. The nucleus is not involved in a chemical reaction. In the electrolysis of water, electricity is used to break the bonds in the water molecule (H2O) to make molecules of oxygen (O2) and hydrogen (H2). Figure 1.4 p. 4

 C. Nuclear Changes - very brief; such as the protons and neutrons change in the nucleus (further work will be done in Issue 2)

 Text p.117-125

NOTES: In a nuclear change, the nucleus is changed by the addition or subtraction of protons and neutrons. Some particles are emitted from the nucleus in the form of radioactivity. In these nuclear changes, new elements are formed.

QUES 3: First, pick an example of any everyday object, then describe one physical and chemical property. Second, give some examples of chemical and physical changes.

If you run out of those kinds of ideas, then use examples from some things that you do in the kitchen.

Text p. 3-6

Notes: For Example: When you bake a cake, is this a physical or chemical change? You should observe that the cake rises due to blowing bubbles of carbon dioxide. Since new substances are formed, it is a chemical change.(You could have answered this much by yourselves) Further explanation: It is a chemical change because you have added baking soda or baking powder as an ingredient. You have also added some form of acid, probably hidden and you do not know about this, which in turn reacts to produce bubbles of carbon dioxide.

Notes: For example: The difference between the physical and chemical properties of copper. Pure copper has a bright orange type color as a physical property. However a chemical change can occur with copper in the air to produce a green color which is really a combination of copper oxide and copper carbonate. A chemical change has produced new compounds which have a different physical property, namely the green color on the surface of the copper metal. Silver has the same property of tarnishing (turns black due to the presence of silver sulfide). Gold does not have this chemical property and does not tarnish or change colors.

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4. Law of Conservation of Mass

A. What is the Law of Conservation of Mass?

Text p. 57

 B. Consequences of Throw Away Society - Pollution

1. Quality of Matter: High Quality (high concentration, relatively pure).  Examples:  Salt, Sugar, Aluminum Can

vs.

2. Low Quality Matter: (low concentration, impure, polluted.)  Examples:  Sugar in soda, aluminum ore before refining

 

QUES. 4: State the Law of Conservation of Mass and apply it to the burning of a candle or gasoline in your car.

How does it relate to a "throw-away" philosophy in society?

Give an example of "high and low" quality matter.

NOTES: Organized and concentrated matter is high quality matter that can be converted into useful products. Low quality matter has been changed, disorganized, or dispersed after it has been used and thrown away.

In a "throw away" society, everything that is thrown away is still with us in one form or another; there is no "away". Pollution is caused by misplaced matter or waste products that were changed into other forms of matter that went down the drain or up the smokestack or to the landfill.

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Part III.  Content B - Objective 3:  Hypothesis Analysis

Ques. No.      Student ID #

     

Ques. 5        3, 11, 21, 2, 20, 30, 10, 18

Ques. 6        4, 12, 22, 1, 19, 29, 28 

Ques. 7        5, 13, 23, 7, 15, 25, 17, 27

Ques. 8        6, 14, 24, 8, 9, 16, 26

Do the assigned Ques. 5-8 as follows above.

After you have written your answer in a word processor, then go to the Discussion Board to post it.

Atomic Structure (read Chap. 3 - all of it)

A. Structure of the atom - Nucleus   Text p. 62-64

Rutherford Gold Foil Experiment:

"The popular theory of atomic structure at the time of Rutherford's experiment was the "plum pudding model". This model was developed in 1904 by J. J. Thomson, the scientist who discovered the electron. This theory held that the negatively charged electrons in an atom were floating (sometimes moving) in a sea of positive charge—the electrons being akin to plums in a bowl of pudding. The plum pudding model was the prevailing theory on the structure of the atom until it was disproved by Ernest Rutherford in his analysis of the gold foil experiment, published in 1911.

The gold foil experiment was conducted under the supervision of Rutherford at the University of Manchester in 1909 by scientist Hans Geiger and undergraduate student Ernest Marsden. Rutherford, chair of the Manchester physics department at the time of the experiment, is given primary credit for the experiment, as the theories that resulted are primarily his work. Rutherford's gold foil experiment is also sometimes referred to as the Geiger-Marsden experiment."  http://en.wikipedia.org/wiki/Geiger–Marsden_experiment

 Click the link for more details.

Rutherford Gold Foil Experiment Animation:   Alpha particles ("atomic bullets") were directed at a very thin piece of gold foil.

QUES. 5: a.  Before the Gold Foil Experiment was conducted, what was the hypothesis for the structure of the atom?

b.  Explain how the the Rutherford Gold Foil experiment was conducted.

c. What two types of experimental data were obtained and how did one of these types of data disprove the original hypothesis?

d.  What was the new hypothesis on the structure of the atom?

e.  How does the new and still current hypothesis of the atom structure answer the following questions.  Why do most particles pass right through; why are some particles deflected?

f.  Pick any one atom (not hydrogen or helium) and give the number of protons, electrons, and neutrons present, then give the Bohr energy levels and finally the Wave Mechanical electrons Arrangements (see p. 88 in text).

 Example: Sodium, Na: Atomic Number = 11 = 11 protons = 11 electrons; Atomic Mass = 22.99 (round to nearest) = 23 = total protons + neutrons; therefore 23 - 11 protons = 12 neutrons.  Bohr Model = 1st energy level = 2, 2nd energy level = 8, 3rd energy level = 1

Wave Model = 1s2, 2s2, 2p6, 3s1

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B. Parts of the atom - electrons   Text p. 60-63

Thomson used the cathode ray tube to conduct experiments to discover the nature of the "rays" that were produced by it.  Before the advent of flat screen TV, the cathode ray tube was at the heart of a television set.

J.J. Thomson Cathode Ray Experiments - more text but explains the three experiments

Cathode Ray Tube Animation Experiments -  Animations show the three experiments (Experiment 1 and 2

QUES. 6: a.  What is the hypothesis (word used was "inkling") of the first cathode ray experiment (this is the second one in the animation above)?  What was the experiment performed?  What was the conclusion related to the hypothesis?

b.  What is the hypothesis of the second cathode ray experiment (this is the first one in the animation)? What was the experiment performed?  What was the conclusion related to the hypothesis?

c. What is the hypothesis of the third cathode ray experiment (this is the last one in the animation)? What was the experiment performed?  What was the conclusion related to the hypothesis?

d.  Under Later Developments, what was the final hypothesis regarding the electrons and the structure of the atom.

e.  Pick any one atom (not hydrogen or helium) and give the number of protons, electrons, and neutrons present, then give the Bohr energy levels and finally the Wave Mechanical electrons Arrangements (see p. 88 in text).

 Example: Sodium, Na: Atomic Number = 11 = 11 protons = 11 electrons; Atomic Mass = 22.99 (round to nearest) = 23 = total protons + neutrons; therefore 23 - 11 protons = 12 neutrons.  Bohr Model = 1st energy level = 2, 2nd energy level = 8, 3rd energy level = 1

Wave Model = 1s2, 2s2, 2p6, 3s1

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C. Parts of the atom - protons

Positive and Negative Charges:  When working with ideas about electrons and protons, the theories of the interaction of positive and negative charges are important.  In general opposite charges such as a positive (+) or negative (-) attract each other.  Like charges repel each other.  This effect is often observed with static electricity.  Rub your hair with a balloon and the hair stands up and trys to repel each other because the hair strands have the same charge.  If you walk, shuffle across a carpet and then touch some one or something, you get a spark or slight shock because the two objects have the same charge.

Text p. 61-62

Goldstein's hollow cathode -

Sorry, I could not find an animation for this experiment.

"Rays of positive electricity

Proceedings of the Royal Society A 89, 1-20 (1913) [as excerpted in Henry A. Boorse & Lloyd Motz, The World of the Atom, Vol. 1 (New York: Basic Books, 1966)]

In 1886, Goldstein observed that when the cathode in a vacuum tube was pierced with holes, the electrical discharge did not stop at the cathode; behind the cathode, beams of light could be seen streaming through the holes in the way represented in Figure 1. He ascribed these pencils of light to rays passing through the holes into the gas behind the cathode; and from their association with the channels through the cathode he called these rays Kanalstrahlen. The color of the light behind the cathode depends on the gas in the tube: with air the light is yellowish, with hydrogen rose color, with neon the gorgeous neon red, the effects with this gas being exceedingly striking. The rays produce phosphorescence when they strike against the walls of the tube; they also affect a photographic plate. Goldstein could not detect any deflection when a permanent magnet was held near the rays. In 1898, however, W. Wein, by the use of very powerful magnetic fields, deflected these rays and showed that some of them were positively charged; by measuring the electric and magnetic deflections he proved that the masses of the particles in these rays were comparable with the masses of atoms of hydrogen, and thus were more than a thousand times the mass of a particle in the cathode ray. The composition of these positive rays is much more complex than that of the cathode rays, for whereas the particles in the cathode rays are all of the same kind, there are in the positive rays many different kinds of particles. "

http://web.lemoyne.edu/~giunta/canal.html

QUES. 7: a. What was the hypothesis of Goldstein that led him to try the modification of the cathode to include holes?  I will help you a little on this as it is not clear.  But reverse thinking will help.  Since Thomson had discovered cathode rays coming from the cathode (negative charge) going toward the anode (positive charge) which he called electrons and had negative charge, what do you think was the thought process for rays going in the opposite direction (from the anode (-) towards the cathode (+) and how could you find them?

b.  What was the result of the experiment relating to rays going coming from the anode through the holes in the cathode?

c. What did the experiments show when a magnet or electric field was used to try to deflect the "canal rays" and what had to be the charge of these particles?

d.  In the second paragraph of Goldstein's hollow cathode explain how the canal rays were formed?

e.  Pick any one atom (not hydrogen or helium) and give the number of protons, electrons, and neutrons present, then give the Bohr energy levels and finally the Wave Mechanical electrons Arrangements (see p. 88 in text).

 Example: Sodium, Na: Atomic Number = 11 = 11 protons = 11 electrons; Atomic Mass = 22.99 (round to nearest) = 23 = total protons + neutrons; therefore 23 - 11 protons = 12 neutrons.  Bohr Model = 1st energy level = 2, 2nd energy level = 8, 3rd energy level = 1

Wave Model = 1s2, 2s2, 2p6, 3s1

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D. Parts of the atom - neutrons

 Text p. 64-65

E. Structure of the atom - arrangement of the electrons and the Bohr atom.

 

Text p. 83-87

Atomic Emission Spectra - Origins of Spectral Lines of the Elements - and Bohr's Explanation

Periodic Table click element to see emission spectra - click on the elements to see the line spectra.

QUES. 8:  Use the first link above and the text:

a.  What is the behavior toward light for most solids, liquids, and gases?  

b. What was different and surprising about the behavior of low pressure gases which are really the properties of lots of individual gas atoms?

c.  What are the two hypothesizes of Niels Bohr to explain this behavior of the line spectra?  (p. 85 first paragraph under Bohr Model and top of p. 86)

d.  How do these help to explain the line spectra of the atoms?  Check out the animations in Atomic Emission Spectra

e.  Give the Bohr electron arrangement for any atom with atomic number 3-18.

f.  Pick any one atom (not hydrogen or helium) and give the number of protons, electrons, and neutrons present, then give the Bohr energy levels and finally the Wave Mechanical electrons Arrangements (see p. 88 in text).

 Example: Sodium, Na: Atomic Number = 11 = 11 protons = 11 electrons; Atomic Mass = 22.99 (round to nearest) = 23 = total protons + neutrons; therefore 23 - 11 protons = 12 neutrons.  Bohr Model = 1st energy level = 2, 2nd energy level = 8, 3rd energy level = 1

Wave Model = 1s2, 2s2, 2p6, 3s1

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Text p. 87-94

Quantum Wave Model Atom: The Bohr model of the atom using electrons as particles in a solar system type arrangement was later replaced with the quantum wave model. Electrons behave as waves, not as particles, and as a results the electrons are described mathematically to have only certain probabilities in certain regions of space around the atom. The energy levels are further divided into sub energy levels denoted as s, p, d, and f.

F. Specific Elements - use Periodic Table to give electrons, protons, neutrons, Bohr diagrams, Lewis symbols, General organization of Periodic Table

Text p.70-73

 Periodic Table - gives a graphic picture of the Bohr Diagram of each element. Pick an element, then you can look at the Bohr diagram by clicking on electronic data or the picture of the Bohr Diagram.

A little music to brighten your day - must listen. Tom Lehrer's Element song.

 

G. Isotopes - of elements have the same number of protons, but different numbers of neutrons. Isotopes have different atomic masses as a result.

 Text p.67-69

Explain the concepts of the Quantum Wave model of the atom. What are meant by electron configurations? Give an example.

Text p. 87-94

Quantum Wave Model Atom: The Bohr model of the atom using electrons as particles in a solar system type arrangement was later replaced with the quantum wave model. Electrons behave as waves, not as particles, and as a results the electrons are described mathematically to have only certain probabilities in certain regions of space around the atom. The energy levels are further divided into sub energy levels denoted as s, p, d, and f.

This Question will be on exam # 1: After reading through this material and/or reading responses for questions 7, 8 and 9, give a brief explanation of the structure of an atom of carbon, nitrogen, oxygen,  sulfur, phosphorus, sodium, magnesium, or chlorine as you might explain it to a friend. Use some details about the number of electrons, protons, and neutrons. Also talk about the particles in the nucleus from the Rutherford experiments and the specific location of the electrons from the Bohr Atom theory and the Wave Mechanical Model (electron configuration). 

IV.  Issue Question:  Should Fluoride be put into Municipal drinking water?

Objective 4: Decision making

This question has been around since the 1950’s with much controversy mostly having to do with it being an involuntary choice.  Today the same issues are present along with questions of safety.  The controlled release of fluoride into drinking water is for the purpose of decreasing tooth decay by preventing cavities.  For the same reason, fluoride is put into toothpaste.  The salvia in the mouth with the fluoride reduces the rate that tooth enamel erodes and increase the remineralization of the enamel in the early stages of a cavity.  A new problem may arise with the large use of bottled water - no fluoride is present and may again lead to more tooth decay.

RESEARCH LINKS:

Fluoride Information Network -

Water Fluoridation - very complete wikipedia article with both sides of issue

Fluoride in Water - mostly pro

Truth about fluoride in water - mostly con

Fluoride Risks - mostly con from Chemical and Engineering News - a very reputable journal

ISSUE QUESTION REPORT:
Should Fluoride be put in Municipal Drinking water?

The report should be 4-6 paragraphs and include the following:

Why is fluoride put into the water?

What is the history of such use both positive and negative?

What is the evidence for positive benefits of fluoride in water?

What are some of the negative consequences of fluoride in water?

What is your position on the main question?

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V.  Response or Ask a Question - respond or comment to someone else, or use General Questions to ask a general question that the Prof or others might answer.  Extra responses earn extra credit (1 pt/ques. up to 2 points)

Response Format:  What or why is something interesting?  Then add a new perspective or viewpoint.  Needs to be longer than one sentence.

Ask a question Format:  Give a little background of what you already know or what is your interest, then add what you already know, then finally ask your question.

Content Question A and B

Ques. No.      Student ID #

Ques. 1        3, 7, 9, 16, 17, 27, 21

Ques. 2        4, 6, 15, 18, 26, 28,   12, 22          

Ques. 3        1, 5,10, 19, 25, 29, 5, 13, 23

Ques. 4        2, 8, 11, 20, 30,  14, 24

Ques. 5        3, 11, 21, 5, 20, 30,  18, 27

Ques. 6        4, 12, 22, 6, 19, 29, 28 

Ques. 7        2, 13, 10, 23, 7, 15, 25, 17, Ques. 8        1, 8, 14, 24,  9, 16, 26

Charles E. Ophardt, Professor of Chemistry, Elmhurst College, Elmhurst, IL 60126, charleso at elmhurst.edu, Copyright 2009