Sunday, November 3, 2013

Phasing Out the Demo

I’m struggling to make peace with phasing out class demonstrations.  I am in the middle of the transition from a traditional classroom into a student-centered learning environment.  This summer at ChemEd13 I realized that the quest for the perfect chemistry demo is outdated pedagogy that pays homage to the “Sage on the Stage” model of teaching.  As I wrote in my first blog post, Dr. Shakhashiri opened my eyes to the wonderful world of chemistry demonstrations.  Actually, adding class demonstrations to my lessons literally saved my teaching career in my second year.  I dedicated the first year of this blog to documenting how I was implementing new class demos.  Researching demos and learning new chemistry was very exciting for me as I wrote my first series of blog posts.  Yet, now I feel frustrated by the class demo because my students are passively watching me “do science” for them.

Last week I spent a class period doing a series of demos as part of my chemical reactions unit.  After a week in which my kids explored chemical reactions in the lab, I  followed up with some “more exciting” reactions as a way of reviewing their understanding of predicting products and writing chemical equations.  (This is the unit that I presented atChemEd13 in Waterloo this summer.  My fellow chemistry teachers were excited by the lesson.)  The class was going along as planned, my students were sitting around a central lab table, white boards and markers in hand.  After every demo I performed, they wrote out the chemical reaction to describe what they saw.  The eye-opening moment for me was the big finale during my B-block class.  I decided to end the day with my “thermite two ways” demo.  I took the class outside to watch the famous thermite reaction.  There were plenty of oohhs andaahhhs at the awesome power of the thermite, the sparks flying, and the dripping molten iron.  Then, I got out my rusty cannonballs (one wrapped in aluminum foil) and showed them “hand held” thermite.  Banging the two cannonballs together produces a loud pop and sparks.  After I got a good pop and some sparks, I passed the cannonballs to a student.  That’s when the magic happened.   My students got so energized by watching their classmates create the hand-held thermite reaction.  Each successful bang was greeted with cheers and applause.  One boy was crowned thethermite master; he forced some amazing blasts out of those two cannonballs.  I walked away from this day smiling at the great enthusiasm the kids had during class.  But, later that day, as I started reflecting on the lesson, it hit me like a ton of bricks; it only got exciting when the chemistry was in the students hands.  I was reminded once again that learning happens when the students engage in the process.

The flipped classroom has changed everything for me.  When I moved myself from the center of the stage, my goal shifted away from teaching the perfect lesson, and toward creating an engaging learning environment.  I realized that kids don’t learn by watching me blow up things and light stuff on fire.  Yes, I know it’s really fun for everyone, especially me, to do a big “tada” demo.  I am the first to admit that I love demos.  Yet, when I put learning as the central objective in my class, rather than performing, the outcome is unpredictable, rich, and sometimes magical.

Friday, September 27, 2013

How to Jump Onto a Moving Train?!

Heating baking soda using a gas collection apparatus.
Starting over is always tough.  At the beginning of the new school year I was struggling to find the right entry point into the study of chemistry for my students.  I decided to start with an experiment that requires fire, has glassware to assemble, and generates graphable data.   I had the kids decompose baking soda by heating it in a Bunsen burner.  Although this sounds very simple, it turned into a rich experiment to launch my lab-based curriculum.

I found my inspiration for this experiment from the IPS book (Introductory Physical Science - 8th edition by Uri Haber-Schaim).  The opening experiment in this inquiry-based physical science program is to heat baking soda.  As I read through the teachers guide for more details, I came across this statement:  "The original mass of baking soda doesn't matter, more baking soda will increase the volume of gas produced."  That's when I decided to make this into a controlled experiment with an independent variable and dependent variable.  This simple experiment can be easily manipulated to collect enough data to explore the relationship between the mass of baking soda used and the volume of gas produced.

On the first day of experiment, I taught all the students how to light and extinguish the Bunsen burner.

Gas bubbles can be seen in the inverted bottle.
 Once the jitters were out of the way about using the flame, we launched our first round of data collection.  To start off, I had all the students measure out the same mass of baking soda.   I took time to demonstrate how to assemble the apparatus, and then checked each group's set-up before they began heating the baking soda.  I love experiments with apparatus to assemble. This may be the only place in their technology-rich lives that these kids screw a ring clamp to a stand and tweak a tube so that gas bubbles come out inside a bottle.  At the end of the first day, every group could answer to the original question: What happens when we heat baking soda?

Each group used a different mass of baking soda in the second trial.
One the second day, I posed the idea of creating a controlled experiment based on what we had learned about the system.  Through a class discussion, the students generated a question to answer through experimentation.  Once they all agreed on the experimental question:  "Does the amount of gas produced change if we vary the amount of baking soda", each group chose a different amount of baking soda to decompose.  As a class, my students generated a set of data that could be used to formulate an answer to this question.  We plotted a graph of the data, and it gave us a very nice linear trendline.  Now, I have to admit that I was pleasantly surprised when we got a nice graph out of this experiment.  There was so much room for error in this experiment that I was pretty sure that our data would require a lot of handwaving and error analysis to make any sense.

I really enjoyed starting the year with this lab because it has so many introductory concepts all wrapped into one.  The kids learned how to light  the Bunsen burner, they designed and implemented a controlled experiment, they leaned how to measure the mass of a powder and the volume of a gas, they assembled apparatus to collect a gas, they plotted a graph of their data, and answered an experimental question.  I call this a home run in the first week of chemistry class.
A graph of my class data, not bad for the first experiment of the year.

Friday, August 2, 2013

Presenting at the Generations Symposium

The Generations Symposium Presenters
The Generations Symposium is a special event at ChemEd in which young teachers and students work with mentor teachers to present chemistry demonstrations.  Micaela and I were fortunate to have the opportunity to participate this year in Generations.
Micaela doing the Singing Flame Tube demo.  It was a huge hit!
We were the lead-off group for the symposium because we were a last minute addition to the program.  When I introduced Micaela to the packed crowd, and explained that she was just hired to teach chemistry only three weeks ago, she got a huge round of applause.  I must say that she was an incredibly good sport about the presentation, seeing as I only told her about it after we arrived in Waterloo.  And, I think she had a lot of fun doing the demo.
Charging the tube with rubbing alcohol.
We presented our "Singing Flame Tube" Demo to the group.  This demo is a nice (and safer) variation of the classic Whoosh Bottle demo.  I have an 8-foot polycarbonate tube that's about 2" in diameter, which I brought all the way from Pomfret for this event (it was totally worth it).  First you stopper one end, then pour about 50 mL of rubbing alcohol in the tube.  Next you stopper the other end, and twirl the tube for a few minutes to distribute the alcohol evenly and vaporize some of it.  Here's the most important step:  you must drain out the excess alcohol into a beaker.  Once you've drained the excess liquid, you hold the unstoppered, alcohol-charged tube over a candle.  It's a show stopper!

Andy and his granddaughter doing a demo together.
Another wonderful part of the Generations Symposium was Andy Cherkas's presentation with his granddaughter.  Andy is one of the "old-timers" at ChemEd, a teacher who's been part of this great conference since it began 40 years ago.  He and his granddaughter gave a fun presentation about the invisible spaces between molecules.  Andy is literally transferring his love of science to the next generation.

Star Wars Re-enactment through chemistry demos
The group from Duke University, led by Ken Lyle brought down the house with their Star Wars reenactment through chemistry demonstrations.  They presented a choreographed demo show, set to sound clips from the Star Wars movies, that included a battle scene with light sabers and the struggle between good and evil.  They used flame tubes, chemiluminescence, photosensitive tiles, a flame tornado, and hydrogen balloons in their presentation.  In a word, Awesome!

The Star Wars group had it all:  flames, glowing reactions,
hydrogen balloons, choreography and costumes!
The best part about the Generations Symposium for me was to see how young teachers and students are excited about chemistry education.

Monday, July 29, 2013

ChemEd13 Lab Workshop: Exploring Chemical Reactions, Bringing Chemistry to Life

Let's face it, chemistry teachers are happiest in the lab!

Today I taught a workshop for chemistry teachers at ChemEd13 on my favorite lab of the year:  Classifying Chemical Reactions.  This is a lab that I have adapted from a Flinn Scientific book; each year implementing small changes.  In the latest edition I added instructional videos embedded into the lab handout for my students to watch while conducting the lab.  This year I finally felt that the lab was "done enough" to present at ChemEd.

I had a good turnout of teachers for my workshop this morning, on Day 1!  These enthusiastic teachers dove right into the lab.  Once we finished the lab stations, I taught the group how to do a series of demonstrations that go along with the unit.  I encouraged teachers to try the demos for the first time.  Even Michaela, my new colleague, got into the act by performing the "Singing Flame Tube" demo today for the group.  It was great fun to share some of my favorite chemical reactions here at ChemEd13.  Thanks to the wonderful folks at the University of Waterloo for providing all the chemicals and equipment for my workshop.

These teachers are writing the chemical reaction for what they just saw.

His first time lighting the famous Whoosh Bottle demonstration

Learning how to do the classic "Death of a Gummy Bear" demo.

My new colleague, Micaela, burning magnesium ribbon.
Jean and I at ChemEd in 2007.
ChemEd is a wonderful opportunity for chemistry teachers from all over the world to come together to share ideas and learn from each other.  I love coming out for this fun conference because it's great to be around so many people who love to teach chemistry!  One of my favorite parts of ChemEd is connecting with my chemistry friends.  Here's a picture of my good friend Jean Hein during my first trip to ChemEd in Texas six years ago.

These chemistry teachers are working through the 8 lab
stations for the Chemical Reactions Lab

Friday, May 17, 2013

Looking at the Absorption Spectrum of a Star

Josh, Sharon, and Honors Chemistry Students in the observatory

Josh is so excited that he can't stand still for a photo!
How many years does it take to get a project off the ground?  In this case, two.  Josh, the astronomy teacher here at Pomfret, and I have been batting around the idea of using our observatory to collect star spectrum data as a chemistry lab.  We do the traditional spectrum lab with gas tubes in the classroom every year.  Why not take the next step and look at the spectra from some stars?  Josh found the tools we needed to make this idea happen.  RSpec makes a diffraction grating attachment for telescope cameras that will generate spectra from stars and the software to analyze the data.  We can also use this same software to analyze the line spectra from our gas tubes in the lab.  Our plan is to collect some data for select elements in the lab using the gas tubes, analyze the data in RSpec, and then move to the observatory to collect data for some stars.  We are both really excited about the possibilities.

Jack and Chris are very excited about science.
This week we took a group of my Honors Chem students over to the observatory to give them a tour of the spectra data and analysis.  We didn't do a full lab with these kids, but we introduced them to this exciting project.  Josh and I were both feeling a bit unsure about the night at the obs because the end-of-the-year crunch is upon us.  However, being there with the kids showed us how exciting this kind of science project can be for everyone.  Josh was so inspired that he wants to change our curriculum to an "Astronomy First" department instead of "Physics First".  Next year we will start the year with this project.  Today at lunch we made a plan to use some of our summer vacation to solidify our goals and methods for collecting and analyzing star spectra.  Why not start the year with this exciting project.   Who knows what direction it will take us...
We also got a wonderful view of Saturn.  Sarah and Rachel were excited to see the rings.

Saturday, May 11, 2013

Bring on the Dots

These girls are shifting electrons around to make complete octets.
 Lewis dot diagrams are a staple of any chemistry course.  The diagrams are an easy way to represent a molecule that shows the chemical bonds and the lone electron pairs.  I really enjoy teaching this to students because kids "get it".  We can quickly go from zero to expert in just one class period.

The electron chips were fun to use.
This year I decided to kick off the Lewis dots with my new toy, Lewis Electron Dot Models from Flinn Scientific.  Each student got a set of cards with element symbols and small chips in several colors.  Using these cards and chips, I introduced the kids to the Lewis Dot representation of electrons in a neutral atom, ions, ionic compounds, and covalent compounds.  It was a really fun class because the kids were actively engaged in the development of this concept.  I loved how each student put their own style into the structures with the colored chips.  You can see from these pictures how each student created their own Lewis dot style with the kits.

We made an easy transformation from the kits to drawing molecules on white boards.  The easy manipulation of the dots led them right into drawing the structures without the aid of the

electron chips.  The next day we took the white boards and our periodic tables outside into the sunshine to draw Lewis dot diagrams of multiple bond molecules and polyatomic ions.

Nick was proud of his yellow border for his structures.
Here's his carbon tetrachloride molecule.

Thomas and Jane made their own representations of NaCl using
the white boards and the chips

Another colorful carbon tetrachloride

Friday, May 3, 2013

Reviving the 20% Project

Today we started Phase II of the 20% Project in my honors chemistry class.
Quinn is making his first polymer.

Here's the description of the project for the winter term.
20% Project Details

The open-ended, student-driven project idea was planted in my mind at a Flipped Classroom workshop I attended last summer.  One of the presenters shared his class project in which he allows his student to do a project of their own design at the end of the school year.  He based the project idea off of the model that Google uses that allows employees 20% of their work time to explore their own ideas.   I was hooked on the idea right away, but how to pull it off?  I chewed on the idea for a while over the summer and through the fall. Winter term is when we do "alternative assessments" in place of exams, so I took a deep breath and launched the project with my students.

Tim just planted his fast growing seeds.
The first hurdle we had to cross was choosing a topic.  A few of the kids knew right away what they wanted to do.  One boy has a dad who works at a plant nearby that makes plastics.  He decided to study polymers for his project, both in the chemistry lab and at the plant.  Super cool!  Another girl in my class is very interested in medicine.  Her Mom is a doctor, so she is very comfortable visiting hospitals and she's up to date on the latest practices in heart surgery.  She's using the project as way to learn more about heart disease, a topic she really.  Other kids, after a little digging, uncovered an area of interest that turned into a topic idea.  For example, one of my students started of with this statement "I want to study plants".  So I said, "Ok, that's a good start.  What is it about plants that interests you?"  Let's just say we went back and forth for a while talking about his interest in plants.  Eventually he landed on the idea to study how much lead is absorbed by plants if he grows seeds in the presence of lead nitrate.  He said, "I could use the precipitation reactions that we just finished studying to figure out how much lead is in there, right?"  This was pure gold to me.  I smiled and thought "This is why I'm doing the 20% project."  The hard cases were the students with no real direction and no definable interests in science.  These kids, about 1/4 of the class as it turns out, limped along during the research and planning phase with very little focus and  a serious lack of motivation.  One boy never really defined a topic.  He put together a vague presentation with several very big ideas that could become good topics if he narrowed them way down and actually looked up some stuff.  He was the extreme case of a syndrome I call "topic choice ambivalence".  All the kids gave a Pecha Kucha style presentation at the end of the winter term to report what they learned and give some plans for their project in the spring term.

Ross is getting his electrolytes project off the ground.
I decided to address this topic choice issue head-on with my class before embarking on Phase II.  A few weeks ago I gave all the students the choice to (1) continue with their project as planned, (2) find a partner and work on their idea with them, or (3) choose a new project from a list of my ideas (lab ideas that I haven't had time to work on myself).  The class divided roughly in half:  one half continued with their original idea, the other half chose one of my project ideas.  The "re-do" option was a nice break for those kids who were struggling in the winter   With a fresh outlook and a tangible idea to work on (all my ideas were lab based), these kids began to show some enthusiasm for the 20% Project.  The kids who stuck to their original idea had the chance to recommit to the plan they made in the winter term.

And now back to the work of the day.  Today was really a day to get organized.  All the kids doing experiments were gathering equipment and reading directions (I refrained from asking "why didn't you read this before today?"), and doing calculations (same comment).  It was a lot of fun and very busy getting all the groups moving forward on their experiments.  It seems like the kids who chose an experiment-based project will end up getting the most out of this experience.

Danny is not sure what to do next
on  his study of sneakers.
I only have three students who chose a topic that does not include an experiment.  Doing an experiment was not a requirement of the project, so I didn't ask them to change topics.  All three of these kids decided not to change topics, and forge ahead with their original ideas.  However, watching all the activity in the room made these three kids a little sad and they seemed a little left out.  Maybe next time I will make the experimentation component a requirement of the project to make sure everyone is in on the fun.

With only two and half weeks of school left, it seems very likely that this project could eat up the rest of the year, like Pac Man on munching on those dots, one chomp at a time.  But in the end, I think this project has the potential to be the most memorable part of the entire course.  Is that worth the 20% of our class time?  I'll let you know when it's all done.
Flowers for a pigment pH indicator project, one of my suggestions.

Friday, February 22, 2013

If You're Not Part of the Solution...

then you're part of the precipitate!

My Honors Chem class worked through a qualitative analysis lab to confirm (or deny) the presence of zinc, iron, and silver ions in a solution.  The students took advantage of the precipitation reactions that occur when these metal ions are mixed with chloride, hydroxide, ammonia, and other anions in solution.  

First the lab teams worked with a known solution that contained each of the three ions, to learn how to make a positive ID of each one.  Then they were given an unknown solution that contained one or more of these ions.  The lab teams worked through the series of precipitation reactions to reveal what was in their unknown solutions.

The groups created a presentation in Google Docs to present their work.  My instructions were pretty simple:  one slide for each ion, one-three slides for your unknown, and an intro and a conclusion slide.  What I got from these creative students was very fun to read and included accurate information about the chemistry involved.  I enjoyed them all, but this one stood "out in the crowd" for both creativity and good chemistry.  Take a look!

Tuesday, February 12, 2013

Meet the Chemistry Myth Busters

Colby Tucker and Sharon Geyer are the courageous leaders of this  pack of Chemistry Myth Busters.
Meet the 2012-2013 Chemistry Myth Busters!  These inquisitive young scientists are setting out to test some common myths.  Here are the Chemistry Myth Buster teams and the myths they are testing.

Afia and Taylor are testing the myth that the boys bathrooms have more germs than the girls bathrooms.

Pelumi and Carlin are testing the affect of low pressure on body parts.  They want to test the myth that body parts explode in space.

Grace and Nick are testing the myth that when you drop a piece of butter toast it will always land buttered-side down.

Thomas and Jane are testing the myth that you can pop popcorn using the heat from the sun.

Austin and India are testing the myth that people will always here hidden messages in recordings of spoken english  that is played backwards.  (I think I hear Stairway to Heaven playing in the background.)

Josh is testing the myth that baseballs that are dried out will travel farther when hit with a baseball bat.  Sounds like a fun experiment!

Khalil and Thomas are testing the myth that Coke can be used as a windshield de-icer.  (Sounds messy to me!)

Alex, Olivia, and Nikki are testing the 5-second rule.  (A classic!)

Elisabeth and Abby are testing if boys have more cooties (germs) than girls.

Cecilia and Isaiah are testing the myth that club soda will remove stains from clothing.

Monday, January 7, 2013

The Envelope Please

In the fall term I challenged my students to write an essay about the fundamental concepts of matter.  We did a series of activities in class to learn about the classification of matter such as a POGIL (inquiry based learning activity), separating a mixture, and the classic iron and sulfur lab.  Through these activities and labs, the students built an understanding of elements, compounds, mixtures, physical and chemical properties, and physical and chemical change.  In the past I would end this unit with a test on these concepts, but this year I decided to try the essay challenge as the final assessment.  Using their experiences, they were charged to write a thoughtful and interesting essay about matter.

As an extra incentive, I promised to post the best essay of the class on my blog.  I thought that one essay would stand out as the clear winner, but I was very wrong.  I had several very good essays that exceeded my expectations.  The choice of one winner put me in a complete deadlock.  I just couldn't choose my favorite ONE essay.  So I sat on it for way too long, just stewing and putting off my students inquiries.  Well, tonight I'm going to announce the winners of the essay contest.  In the spirit of the fall term sport assembly, I have chosen two students to be the winners of the matter essay challenge.

And the winners are...

Bailey Mae Bone and Quinn Taylor

Congratulations on your excellent writing.  Both essays are posted on the blog.  Enjoy.

Quinn Taylor

Bailey Bone

Why Does Chemistry “Matter”? by Quinn Taylor

Why Does Chemistry “Matter”?
            Matter. It is what makes up the entire universe, and makes us what we are today. From magnificent glowing stars millions of light years away, to the tiny, dim night light in a child’s room, it consists of matter. This concept of understanding the make-up of everything we know and will know is not a straight forward thing either. It can take on many different shapes and forms, such as compounds, elements, mixtures and much more. Matter can even go through numerous and exciting changes, making it an intriguing topic to study upon. As scientists have been discovering for thousands of years, science is an incredible thing, and can be very fascinating once you delve into its secrets.
            The most basic building block of matter is of course the element. An element is the smallest thing that a substance can be broken down into without splitting atoms. A great example of a common element is the gas Oxygen (O). Another example of elements would be the breaking apart of the compound Sodium Chloride (NaCl), or table salt, as we casually call it. When salt is broken down into its smallest parts, you will have the elements sodium and chlorine left over. These combinations of two or more elements are called a compound. In a compound, the elements are chemically bonded together through a chemical reaction to form something new. As learned in the POGIL activity, the majority of our items that we use and see on a daily basis are compounds. A few examples of these items are water (H2O), Chalk (CaCo3), carbon dioxide (Co2), acetaminophen (C8H9No2), and much more. You would be surprised to know that these reactions are occurring everywhere all the time, even without us knowing it. Not all of these reactions are big, or drastically change the substances interacted with it, but life would be impossible to sustain without them.
            These common changes can come in many ways, shapes, and forms, including physical and chemical changes. A physical change is a change to the substance that does not affect what substance is or its chemical makeup. These changes, such as tearing, cutting, dissolving, freezing, evaporating, condensing, affect the substance without changing it molecular makeup, therefore classifying it as a physical change. Chemical changes, on the other hand, do change the substance and its molecular makeup. Examples of these types of changes can be rotting, rusting, digesting, eroding, burning and reacting with an acid. If a chemical change occurs, you cannot get back the original substances without using some form of a chemical or having a chemical reaction occur. It is easy to know when a chemical reaction is occurring to your substance though. Common side effects from a reaction may be smoking, heat expulsion, smell dispersion, bubbles (creation of a gas), formation of a precipitate, and a change in color. As we saw in the iron and sulfur lab, many of these things will occur at the same time. When our reaction occurred, we observed heat expulsion, smoking, and a change in color, and of course, the nasty smell that this experiment is famous for. During this reaction though, not all of the material was used or fused, leaving a mixture left over in the test tube.
            A mixture is a combination of two or more substances either dry (such as sand) or in a liquid (such as sugar water). Compared to a pure substance, mixtures are fairly easy to spot. A pure substance is a material that has the same concentration of molecules throughout its entirety, while also only consisting of one type of molecule. Examples of a pure substance might be salt, sugar, and the other items listed previously, as all elements and compounds are pure substances. If you were to look at a mixture at a molecular level compared to a pure substance, it would look drastically different. The mixture would have many different molecules, particles and substances within it, while the pure substance would only have one. Even with the naked eye, these differences are as obvious. A pure substance is usually uniform, while a mixture contains clumps, bubbles, different colors, grain sizes, and textures. Even more surprising is that it is actually easier to separate one of these crazy mixtures than to separate a plain compound, as a chemical reaction is needed for the compound’s separation. As we learned in the Separation of a Mixture Lab, this makes sense as a mixture can be separated fairly easily. Ways to separate a mixture could be boiling, evaporating, sifting, magnetism, filtering, and much more. When you actually dig down to the bottom of these many different forms of matter, it is actually easy and fun to tell them apart and to separate them in the lab!
            Chemistry is one of the biggest and fastest growing branches of science out there right now. From searching for cures for diseases such as cancer, HIV, and even the common cold, to just trying to be the discoverer of a new substance, chemistry has brought, and is still bringing joy and learning to millions of people around the globe. As we have learned through our many experiments over the past weeks, matter is the basic building block of everything. Once you get past the nitty gritty, and nuts and bolts of these basic principles (and even these aren’t too difficult), many will discover that this field is fascinating, and has the potential to benefit and affect us as students, and possibly even our society, in the rest of lives soon to come.