High School Chemistry part 3: Resources for Teaching Chemistry

Chemistry resources are not always limited to what you see in a homeschooling catalog or at a homeschool convention, so here are a few for you to print and save until you need them.

Textbooks:
ChemCom: Chemistry in the Community by the American Chemical Society.  This popular high school level, college prep text is a completely new approach to the topic.  It is not a watered down version but is a good preparation for the SAT II: Chemistry exam.  It covers all of the usual topics, a little more organic chemistry, and a little less physical chemistry.  Going from one chemistry related problem in the community to another, a student studies the theory necessary to deal with the problem.  Lab is done frequently throughout the year and is included in the text.

General Chemistry by Jean Umland:  This college level text is written at the 10th grade reading level.  Designed for high ability, average readers who are college freshmen, this book is a good choice for future science and engineering majors who are homeschooling through high school.  Tested by some homeschoolers in Houston who reported in to the author, this book can be used in self-teaching situations.  It comes with a student study guide, a CD ROM, and keys.  Have your student use this text and prepare for the Advanced Placement test in May.

Chemistry by Jane Chisholm and Mary Johnson.  An excellent summary of the basic parts of chemistry: matter, atoms, physical changes, chemical changes, reactions, metals, acids and bases, organic chemistry, formulas, experiments, and more.  This would be a good book to read to your children leading into discussions.  Usborne recommends age eleven and up.  Fifth grade through seventh seems like a good range.  Some experiments are included.  I was unable to find this on the internet currently in print, but it looks like one that you should be able to find at your local library.

Videos:
The World of Chemistry is a set of video lessons teaching an introductory course at the non-science major, college level freshman year.  A scaled down version for public high school is also available.  I have seen one episode of the high school version and it seemed to be fairly clear and simple.  The set of videos can be purchased in 26 half hour lessons separately or as an entire course.  There are correlating texts available.

Books of experiments and kits:
Doing high school chemistry at home means doing lab, too.  You can do chemistry lab at home easily!  There are many good lab manuals on the market.  Here are a few.  A good place to go for ideas is to a local college bookstore.  There, you will find an entry-level lab manual, perhaps even one using little or no extra equipment.

Chemistry Experiments by Mary Johnson.  An excellent book of experiments using simple home equipment and chemicals.  The experiments use some imaginative methods to keep the equipment within the common type found around the home.  Some explanations and safety recommendations seem to be too brief.  Recommended.

The Usborne Book of Science Experiments by Jane Bingham.  This book of experiments is for older children (ten and up), and as you would expect, the experiments are more difficult than the Science Activity book above.  Physics, chemistry, and technology are some of the topics.  This would be a good manual to use at the junior high level for science lab (not the text).  Please have the child make a write-up of the experiments he performs, though, with an emphasis on the conclusion step to check for understanding of the principle.  Recommended.

Experiences in Chemistry by Kathleen Julicher.  This is a laboratory manual written specifically for home and other small schools.  At the secondary level, the manual meets requirements for a high school chemistry lab, but can be used at the junior high level with interested students.   Equipment and chemical kits are available to homeschoolers from Home Science Tools.  The simple experiments are based on sound fundamentals and the questions relate the principles to everyday life. 

Cooking and Science by Joseph Julicher.  This workbook uses some classic recipes to teach fundamental chemistry.  Equipment is simple since you already have it in your kitchen.  Prelab and postlab questions require high school level knowledge of chemistry.

Chemical Magic from the Grocery Store by Andy Sae.  Fifty-nine activities are in this book, all designed to generate curiosity about chemistry, demonstrate principles, and dispel “chemophobia.”  Not designed to be a comprehensive lab manual for high school students, it is still full of activities that can be done at home and with little material.

A Laboratory Manual: Experience the Extraordinary Chemistry of Ordinary Things  by B. Coburn Richardson and Thomas G. Chasteen.  This is a lab manual designed for the non-science oriented kid.  There are twenty-seven well-explained experiments.  These labs were chosen for their interest, use of normal things (like aluminum cans) familiarity of reactions, and challenge, although some of the labs require lab equipment most homeschoolers will not have.

MicroChemistry by Tom Russo.  These lab manuals are designed to get students a taste of chemistry lab without the amount of chemicals usually used in laboratories.  The students use very small portion and instead of test tubes, use plastic depression plates.  I have used several of the experiments out of Book I and enjoyed its clarity of explanation.  Comes with a teacher’s guide with complete details about preparing the chemicals and lab equipment.  Also has levels II and III available.
References:
Essential Chemistry by Clive Gifford.  Filled with the key principles of chemistry, this book could easily be a study guide for high school chemistry.  This book is very good and concise in its writing.

Dictionary of Chemistry by Jane Wertheim, Chris Oxlade and Dr. John Waterhouse.  Usborne recommends using this book as a dictionary supplement to a textbook and as a review guide.  Both of those sound like an excellent way to use a book filled with well-made charts and easy to understand commentary.  A bonus in the appendix is the list of good experiments.  Some of these can be done at home with a few moderate equipment purchases.

Magazines and More:
ChemMatters by the American Chemical Society.  This is a great little magazine for the chemistry student.  The publication is sixteen pages full of anecdotes and interesting stories concerning chemistry in the world around us.  You can subscribe to the magazine for $14 for a year (4 issues) or read selected articles online.

Cliff Notes: Chemistry  This online guide is pretty fundamental and has most of the topics from high school chemistry.  Missing some detail, it can serve as an alternative way to review some chemistry, not as a primary source.

Part 1: High School Chemistry
Part 2: Myths about Teaching Chemistry

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High School Chemistry part 2: Myths about Teaching Chemistry

There are some myths about doing chemistry that are important to homeschoolers.  Let’s go over a few of these:

Myth #1.  “You cannot teach chemistry at home if you did not take it yourself.”  (Or its corollary: You cannot teach chemistry at home if you don’t have a degree in chemistry, etc.)  I have met many parents who believe that this is true.  Parents can learn chemistry by reading the text just as their students can.  As well, homeschooling high school is not ‘parent spoon feeding the student’, but is student-directed self-study.  Chemistry can be learned this way as can any other subject.  What is required is a good, understandable text, a good amount of curiosity, and a willingness to be consistent.

Myth #2.
  “It takes $2000.00 to set up an adequate chem lab at home.”  I have heard this one at homeschooling conventions and it is patently wrong.  Since centuries ago, chemistry has been done in homes and can be done there today.  There are many very good books available either currently in print or reproducible with permission, which will provide a good laboratory experience.  The equipment is not terribly expensive, a good kit ranges from $100.00 to $350.00.  Even the Smithsonian chemistry sets in toy stores can be used to give a lab experience to your student.  Note that most lab manuals have been written for schools with laboratories and large-scale budgets.  Most of the common ingredient manuals are really more for elementary students.  So, how can you deal with this?  Simple, don’t worry about the labs you don’t have the materials for.  You should do about 25 -30 experiments during one year of chemistry.  (36-40 is better, of course)  So, choose your experiments from several sources, if necessary.  There are at least several manuals available that were written for homeschoolers specifically.  Experiences in Chemistry is one that was specifically designed to use everyday household equipment.

Myth #3.
  “Chemistry is too hard to do at home and should be taught by experts in school.”  Many homeschooling parents use chemistry as the subject to cover with a tutor, videotapes, or special classes.  These are great alternative ways to do chemistry, but they are somewhat expensive, whereas doing lab in a class for homeschoolers can be fun as well as a learning experience.  If you are thinking about a tutor, look into hiring a retired person from your church.  A retired chemical engineer can teach things about chemistry that no ordinary teacher would know.  If you plan on using videos, remember that a video does not substitute for laboratory experience.  Lab experience means using the equipment yourself, not watching someone else use the equipment.

Myth #4“Kitchen chemistry is the way to go for high school credit for your non-science major or non-college bound student.”  The chemistry of foods is a very complicated subject.  It is difficult to teach the foundations of chemistry simply by using a recipe book.  It is good to remember that Foods and Feeding is usually a very difficult course of study in college.  The fact that we all eat food does not mean that the chemistry of food is easy.  On the other hand, there are some good, edible experiments out there that can provide a great supplement to your chemistry studies, as well as being fun to do.

Myth #5.
  “One text is like another.  I’ll just pick up a used book from the school.”  Each text has good points as well as weaknesses, but they usually can be trusted to include the principles of the topic as well as some good problems for your student to solve.  However, there are differences in the texts.  One text might be good for your student, while another might totally turn him off to chemistry.  Read some of the reviews and see if you can spot the differences between the texts.  Some texts rely upon the student to work all of the math problems; others want the student to use analytical skills to solve non-math oriented problems.   One text may have the semester lined out with assignments, etc., while another may leave all that up to the student. If your student is self motivated he can use the later, while a less organized person will want to use the former.  Choose your text based upon the goals, skills, and interests of your student. (Yours, too)

Part 1: High School Chemistry!

Part 3: Resources for Teaching Chemistry

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Everyday Science: Contrails

It’s fall, and that means leaves falling, pumpkin pie baking, calendars rapidly filling, and ….. contrails forming.  So what exactly is a contrail?

Contrails (short for condensation trail) are man-made “clouds” created by aircraft engines when the temperature and humidity conditions are just right.  Usually occurring at temperatures below -40°C, and at altitudes above 26,000 ft, contrails are formed when water vapor condenses and then freezes on the particulate matter in aircraft exhaust.  To form a contrail, the temperature must be low enough or the humidity must be high enough for water to condense on the exhaust particles.  Since the process of condensation is well understood, it is possible to predict when contrails will form based on prevalent temperature and humidity conditions.

Typically, with fall weather comes cool, moist air aloft and conditions at are perfect for contrail production.  Think about it: do you see very many contrails in the summer months when it is hot and dry?  Sometimes contrails dissipate rapidly with high winds or high turbulence aloft, and sometimes contrails linger for quite some time.  Contrails dissipate rapidly with low humidity, since the newly formed ice crystals evaporate quickly.  With high humidity, persistent contrails are visible, as ice crystals grow in size, absorbing water from the surrounding (humid) atmosphere.  You might see a contrail which has been stationary for some time right next to one which is dissipating rapidly.  These contrails are at different altitudes, with different conditions at each level.

Since different gas composition, exhaust gas temperatures, and water vapor content exist in different aircraft engines, not all aircraft engines will produce a contrail at the same altitude (with identical weather conditions) at the same time.  Contrail formation has nothing to do with the type of aircraft or its speed.

Another form of contrail is produced when a portion of an aircraft such as a wingtip or winglet causes air cavitation in humid conditions.  Have you ever seen these vapor trails, perhaps at an airshow, when aircraft flying low over the airfield pitch up rapidly in high humidity conditions?  And since we’re mentioning winglets (shown below), you might be interested to know why they’re on the wing.  The winglet serves to reduce aerodynamic drag so the aircraft burns less fuel in flight.  This fuel efficiency is created by breaking up the turbulent wingtip vortices (pronounced VOR-ti-sees) produced by the pressure differential between the bottom and top of the wing.  No vortices = less drag.

Southwest Winglets

Back to the contrails, though… have you ever seen patterns in the sky produced by contrails?  Perhaps all paralleling one another or converging on a point?

This is no coincidence.  The world is criss-crossed with jet routes flown by all aircraft above a certain altitude.  At the junctions of jet routes are navigational aids, which you may have seen while driving or flying yourself.  Here is one navigation aid (navaid) in Oregon, shown courtesy of Wikipedia:

The aircraft whose contrails you see are each navigating with navaids similar to the one shown above.  Therefore the aircraft fly over the navaids as they transit the jet routes.  Parallel tracks of contrails are aircraft flying along the same route.  If you are ever curious about a contrail track you observe, you can check http://flightaware.com.  A screen shot near Dallas, Texas shows multiple aircraft tracks transiting along an east-west jet route using navaids.

Contrail predictions have been used since WWII, when the ability to spot enemy aircraft “conning” could make the difference in advance notice of an airstrike or positioning for air combat.  Here’s a graphic from p. 55 of the March 1943 edition of Popular Science identifying two types of vapor trail formation:

How about an activity to predict contrail formation?  NASA has an activity page where you can access  an Appleman chart.  Using the chart, you can construct a temperature profile to forecast contrail activity in your area.  The activity (recommended for 5th grade and up) begins this way:

…”Military planners have been interested in condensation trail (contrail) forecasts since World War II. Contrails can make any aircraft easy to locate by enemy forces, and no amount of modern stealth technology can hide an aircraft if it leaves a persistent contrail in its wake. In 1953, a scientist named H. Appleman published a chart that can be used to determine when a jet airplane would or would not produce a contrail. For many years, the US Air Force Global Weather Center used a similar chart to make contrail forecasts.

The first published reports of contrail formation appeared shortly after World War I. At first, scientists were not sure how contrails formed. We now know that they are a type of mixing cloud, similar to the cloud that sometimes forms from your breath during a cold winter day. Appleman showed that when the air outside of the airplane is cold enough and moist enough, the mixture of the jet exhaust and the air would form a cloud.

An example of a contrail-forecasting chart is shown below. We will use the chart to make our own forecasts, and make observations to determine whether they are true or false.

Appleman Chart

… Using either the temperature information provided by the teacher or the temperatures obtained from an Internet location (see note below), complete the table on the “Student Data Sheet”, then plot the temperatures corresponding to each pressure level on the “Appleman Chart: Student Graph Worksheet”. Connect the points to create a temperature profile of the atmosphere.

Note: Temperature and humidity information can be obtained from weather balloon soundings launched twice a day from several locations around the country. Several locations on the Internet including http://weather.uwyo.edu/upperair/sounding.html provide detailed sounding information. Choose the location nearest your school.”

This activity would make a perfect accompaniment to a physical science class, a weather unit study, or just a fun diversion.  If you have a weather station in your home, it would pair up nicely as an associated activity.  For younger elementary students, the NASA site also has a word search and a downloadable “Clouds and Contrails” craft.  Have fun!

Resources:

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