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.