Oxidation Reduction Batteries

Last year when teaching about Redox reactions in Chemistry, I could feel my students lack of energy and imagine little floating Z Z Z Z zzzzzz over their heads.  I decided this year to do something a bit more interesting, inspired by a blog called Kitchen Science by the Naked Scientists.  They referenced a YouTube video where the author shows charging his iPod with a fruit battery.

I downloaded one such video, and used it as a jumping off point with my students to inquire, "Can you charge an iPod with a fruit battery?"  We spent 6 days on this short PBL project, and it was completely student driven.  Students were shown the video (hoax), and shown a real example in a Two-Potato Clock that I bought at a garage sale last year for $1.  

After students journaled about how they think the clock works, they chose groups and researched their own food batteries.  They had one day in the computer lab to research and develop their own experimental plan, including safety information, materials lists, step by step instructions, and blank data tables.

We had two days in class to perform experiments, and access to several types of wire, metal plates, alligator clips, multimeters, and potatoes.  Anything else needed to be brought from home.  They also used a Kill a Watt meter to measure how much energy their own phone or iPod charger uses, so they can make a direct comparison between their battery and charging the device.

At the end of collecting their data, we spent one day on direct instruction of what redox reactions are, and how they power the two potato clock example from the first day.  They compared their understanding from their journal on day 1 to their understanding after this activity.

Lastly, students used this new information and photos they took during the experiment to develop a two slide presentation for the class.  They included diagrams / photos of their most successful batteries, and the chemical reaction that was causing the flow of electrons (including identifying what was being oxidized and what was being reduced).  This quick two slide presentation provided a nice quick conclusion of their work, as well as reflecting on what they could have done to make their battery better in the future.

At the end of the class on the final day, we compared the data collected by students (amps and volts), and determined there was no way the initial video was real, it was indeed a scam.  One of my students said we'd "busted" the myth.  I'm just glad we learned about Redox with less pain than last year, and hopefully making more of a memory for the future.

Anatomy Gingerbread Men

When looking for a post-midterm activity for my students, I stumbled across an amazing blog with posts entitled Science Cookie Roundup.  She has collected many beautiful cookies with science themes, and I thought I would try my hand at this with my students.  We have one day between completing our exams and a two week holiday break, so this really fit the bill.

My cookies: skeletal, circulatory, and digestive systems

I purchased frozen gingerbread cookies from GFS, along with a tub of white icing, piping bags, and Wilton food colors I had from home baking projects.  I showed students a few example pictures I found online, and they had a blast.



My favorite part of this activity is that it's holiday related without being religious.  At school I need to be sensitive to the fact that  many of my students do not celebrate Christmas, but everyone can have fun decorating a cookie.


The students really enjoyed making their cookies, and were so excited to have me take pictures of their work.  Here are a few of their creations.

ok, so they're not all science...

beautiful detail on her holly and string of lights

little pink heart to accent her skeleton

This one broke his arm, so it's bleeding.

this skeleton is wearing a Santa suit.

Mr. and Mrs. Claus

Tarzan and Jane.  My student says this counts as science because Jane went to study the gorillas...

Two skeletons made by friends sitting next to one another, so they placed them holding hands.

nice contrast with the green and white

Molecular Workbench

One of my favorite Chemistry resources is Molecular Workbench.  This site, run by the Concord Consortium, offers online simulations for chemical concepts that can be very difficult for students to grasp with only paper and pencil.  My students are currently working on the Strong Chemical Bonds 2-day activity, although I've used their Intermolecular Forces module as well, with great success.  Both of these are a part of the SAM "Science of Atoms and Molecules" project.  Their website describes SAM as...

The Science of Atoms and Molecules project offers 24 research-based, field-tested activities for physics, chemistry, and biology. We provide these all freely to teachers and students online. Through the SAM activities' interactive models and simulations, we involve students in active learning. Teachers can register online to receive Teacher Guides for each activity and to gain access reporting functions to track student progress.

One feature I haven't investigated yet, is the ability to modify and make the simulations personalized.  It's on my to-do list for sure, as I'm sure the features are excellent, just like the rest of the site.

Even without personalization, I've found their simulations to be very useful.

http://mw2.concord.org/public/part2/bondtype/customDipoleMini.html

Today my students are using electronegativity values to determine if bonds between atoms are covalent, polar covalent, or ionic.  Most students have the idea that only two types of bonds exist when they enter my classroom, and this allows them to see the continuum of bond types, as well as discussing why these types of bonding occur.  With only a verbal description, very few of my students can grasp this concept, but this allows them to manipulate the bonds themselves, and provides a much deeper understanding.

If you haven't checked out what Molecular Workbench has to offer - you should!

Halloween Bone Comparison

Because of the season, October is the perfect time to study the skeleton.   Several years ago, I attended a session at the NSTA conference that suggested using cheap bones from the Halloween store for a forensic activity.  I decided to use them, but in a different way.  I purchased these bones from a catalog, because it wasn’t fall.  The entire Bag O Bones ran me around $20.00. 

 My students are instructed to choose a Halloween bone and identify the quality of its anatomical features.  Students work in a small group for this, and present their findings in a short informal presentation at the end of class.  They give the bone a grade and justify why they graded it in this way.

 If you'd like to download the instructions and worksheet for this activity - click here.

Students in the past have really liked this lesson, and were very engaged in the detail of their specimen.  It ties in the bone markings we learned the day before and is a nice precursor to working with the real disarticulated skeleton in class next week.  This also meets the goal of having students justify and share their work with others.

Another class success.

Low Tech Memorization Technique

A lot of times we are looking for the newest electronic trick to help us learn new things.  Sometimes we forget that our old low-tech tools offer some good methods as well.

We are memorizing the muscles of the thigh this week, and I made a practice sheet with the pictures numbered so the students could write their answers on a separate page and check the answers written on the back, so it's all self directed.

Some students let me know that they need to write ON the pictures to help them memorize, and since our number of copies is watched over, I didn't want to make 5 copies for each student.  Instead, I gave the student an overhead transparency sheet, and an overhead marker. 

By simply laying the  plastic over the diagrams, she could write on the picture again and again to practice her muscle names for tomorrow's test.

Low tech solution - good learning tool!

Video Substitute Teacher

I'm going to be out for a curriculum meeting one day next week, and there's so little time between now and Winter Break, I don't want to miss a day of instruction with my students.

I've been interested in flipping the classroom for a while, and so for this day, I am using the same idea of videotaping my explanation, only I'm the one that won't be in class, the students will still be working.

To set up my video, I first looked at my standards....

 An atom’s electron configuration, particularly the valence elections, determines how an atom interacts with other atoms. 

The polarity of a bond depends on the electronegativity difference and the distance between the atoms (bond length). 

Given the formula, a compound can be named using conventional systems that include Greek prefixes and  Roman numerals where appropriate.

Given the name of an ionic or covalent substance, formulas can be written.

Then I made a basic scripted list of ideas to talk about
* covalent bonds are between two non-metals
* how valence electrons and Lewis dot structures can help us determine bonding patterns
* electronegativity and polarity of covalent compounds
* covalent naming prefixes

I chose a few animations (and made one on XtraNormal as an attention getter)


I wrote practice problems to sprinkle throughout (while the sub pauses the video)

I made a student guide to go with it, with spaces for note taking and the practice problems printed on it.

Finally I recorded my video.  I used the program that comes with our SMART board, it just records your voice and the movement on your computer screen.  So, the students don't see my face, they just hear my voice and see me working the practice problems and explaining on the screen.

I ended my video with a preview of the next day's online lab.  We'll be using Molecular Workbench, and the last few minutes of the video gave me a chance to show them how to get to the website and launch the program, including what would be expected of them on each day (it's a two day lab).

One troubleshooting piece:  It did take a few tries to get the volume right when transitioning from my voice in the mic to the sound from the animation, but I think it was overall quite a success.

We'll see what my students have to say when I get back from my meeting!

Review Sheet Stations

Yesterday in Chemistry we reviewed for today's quiz.  The topic was ionic naming and formula writing, and I found that my students needed many different types of practice.

I planned two simple parts, two medium difficulty parts, and two more challenging parts.  Rather than just put all the practice problems into a worksheet, I separated the activities into six stations.  Each table had a different task, which isn't that different than other class activities I've done before.

The tasks yesterday were:  (in order of difficulty)

Simple Binary Compounds - naming and writing formulas from names (no transition metals or polyatomics)

Binary Puzzles - with the idea inspired by this activity I found online

Naming and Formula Writing with Polyatomic Ions

Naming and Formula Writing with Transition Elements

Mixed Naming Practice - this had "answers" for the problems and students had to evaluate if the answer provided was correct or incorrect, and then they correct as needed.

Real Life Nomenclature - has three product labels with ingredient lists, students must locate and write formulas for as many ionic compounds as possible from the lists. (about 17 that they can identify.)  I had to provide a more detailed polyatomic ion chart for this activity because some of them listed were obscure.

The change this time is, the stations took at least 15 minutes each, and the students only had to choose 3 of the six.  This allowed the students who were struggling to spend their time focusing on the basics, and the students who needed enrichment weren't forced to answer yet another simple binary formula worksheet.

I circulated through the six tables, and made sure they were staying on task.  I was particularly impressed with the idea that several students needed more practice, so they went out of their way to choose extra handouts from the tables they didn't get to and they'd work on them at home.  (self chosen homework?!?!)  Sometimes students will really surprise you when you make the activity about the learning, not about the points for completion.  The answer keys were available and the students were directed to check their work and ask questions about any they got wrong.

I guess I should add, I rarely give points for classwork and homework.  Most of the grade in my class is based on their performance on labs and quizzes.  It has been a shift for them to understand that they're doing the work to LEARN, not to get ten points.

Of course, you could easily make this task worth points by checking off their completed worksheets at the end of class, although I think it would encourage them to copy others work rather than do their own assignments.