Wednesday, May 20, 2015

AACT High School Ambassador Polls are Open, Please Vote for Me!

I've thrown my hat in the ring for the High School Ambassador position for the new Governance Board of the AACT.  I'm excited to take on this position to help shape the growth of this new organization.  If you are a member of AACT, please consider voting for me for the High School Ambassador position.


Friday, May 15, 2015

Pizza Box Spectroscope

The pizza box spectroscope in action.
How many times can you say spectroscopy in one week?  When we make these awesome spectroscopes, I'm sure I come close to 100 times!  I love this fun spectroscopy project that I got from ChemEd13.  Ed Escudero led a hands-on workshop in Waterloo called "Make and take: construct an inexpensive and calibrated spectroscope."  I went home with my own pizza box spectroscope and a great project for the atomic theory unit.  I hope he'll do the same workshop at ChemEd15 for anyone who wants to give it a try.

The pizza box spectroscope is a great way to add a quantitative experiment to the classic atomic spectra observations that we all do in class.  With this project, my students can take accurate measurements of the wavelength of light and use their measurements to identify unknown elements.  Gone are the days of just looking at the pretty colors of the atomic spectra (which is fun too, don't get me wrong).  My students can take measurements that are as good as 1% accuracy from a pizza box!  You can read about constructing the pizza box spectroscopes here.

The pizza box spectroscope has a diffraction grating at the eye hole (closest to the eye), a slit to let in light on the opposite side of the box from the eye how, and a plastic rod running through the box.  The plastic rod is the critical piece of the spectroscope.  Each rod is scored so that it has one vertical notch on it.  The notch on the plastic rod can be aligned with a color in the atomic spectrum, which allows the student to determine the wavelength of the colored line.  The slit can be illuminated by shining a flashlight on the end of the plastic rod, to make the measurements easier and more accurate.  
Testing their viewing of the continuous spectrum.

We used the mercury lamp to calibrate the spectroscopes.  But before I turned on the mercury lamp, I had the lab groups test each other to make sure they were all seeing the same thing.  We opened a shade in the classroom and looked at the continuous spectrum from the sun.  One person in the group put the white mark on a color and passed the box to their partner without telling them what color they chose.  The other partner had to look through the spectroscope and identify the color the mark was pointing to in the box.  This little warm up exercise was very helpful to make sure everyone could see the colors in the spectroscopes and use the white mark on the plastic rod for measuring wavelenght.

The mercury lamp calibration.  You can see the rod, and the white dot from the slit pointing to the green line.
Next we used the mercury lamp to calibrate the pizza boxes.  The students used the known wavelengths of the three prominent lines to take the initial measurements.  Once they aligned the slit on the plastic rod to a color, the students measured the length of the rod sticking out the of the box.  With three data points, they plotted a calibration curve for their box.  There are two important points to mention about each box:  the students have to measure from the same side of the box each time, and they cannot switch plastic rods with another box.  Either of these changes will render their calibration curve useless.

Working in the dark to calibrate the spectroscopes.

I only have one spectrum tube lamp in my class, so we huddled around it to make measurements.  These pictures of the lights shining on the end of the plastic rods are so cool.  We spent about a week on this project total, including building the boxes. 

Students are measuring an unknown element with the pizza box spectroscopes.  Groups work together to view the spectrum and light the rod with a flashlight for each measurement.

The students were very proud of their pizza box spectroscopes.  I love the low-tech nature of this project because they can build their own instrument "from scratch".  I think this is the only chance they have all year to calibrate an instrument.  I usually calibrate the pH probes for them because it takes too much time and can be a little fussy.  Nothing else we use really needs to be calibrated.  This spectroscope project is a great way to show my students an important step in getting good data.
I can't get enough of this fun project.  

After the mercury tube, I put in the hydrogen tube and have them measure the prominent lines.  I could look at the hydrogen spectrum all day long; I love the colors.  This is when the kids get really excited by their percent error.  Most are less then 5% accurate!  (I get pretty excited about the results too, I won't lie to you about that!)
The hydrogen spectrum with a continuous spectrum "noise" in the background.

The cell phone flash lights are so very handy during spectroscopy week.  We end up working in the dark for several days because they are all working on different measurements at different paces.  With only one lamp, it limits the number of elements we can view at once, so the kids just adapt and work with their flashlight apps to measure the length of the rod as needed.

Students used their iPhone flash light apps to measure the length of the plastic rod.

The last phase of the project is identifying unknown elements.  I put several different tubes in for them to test.  They have to measure three lines from each to make their identification.  Of course, they also realize that each spectrum looks different, so the measurements become the confirmation of the identity, and helps them choose between the elements that look close to their observation.

Here's the helium spectrum with the slit aligned with the yellow line.
I have a set of R-Spec spectroscopes that we use for the astronomy class that I plan to add to the spectroscopy week next year.  After finishing with their own spectroscopes, I will give them a chance to collect data with the R-Spec cameras.  The lab work with the electronic equipment will be more rich with the foundation they get from building their own spectroscope.  I'm actually thinking about expanding spectroscopy week into a term elective for advanced science students who want to design their own experiments using spectroscopy techniques.

Making the Pizza Box Spectroscope

All the pieces needed for the pizza box spectroscope.
The pizza box spectroscope is a fun project to add to your atomic model unit.  Students can make an accurate tool to measure the wavelength of light using a pizza box, a diffraction grating, two razor blades, a plastic rod, and some metal tape.  The project is fun, easy to complete, and produces excellent lab data.  The wavelength measurements are typically within 1% of the accepted value using a calibrated pizza box!  
Chemistry teachers making spectroscopes at ChemEd'13 in Waterloo.
I learned how to do this project at ChemEd'13 at Waterloo University from Edmund Escuadero's session titled "Make and take:  Construct an inexpensive calibrated spectroscope."  Every participant made their own pizza box spectroscope in the workshop and learned how to calibrate it using a mercury lamp.  The process was so fun and relatively simple; a perfect idea to bring back to my school to do with my Honors Chemistry students.  The first year I used it in a collaborative project with the astronomy classes, and this year I did it just with my chemistry students as part of the atomic model unit.  

The original experiment instructions can be found in the PSU Chemtrek Lab Manual  (ISBN:  978-0-7380-2849-1) .  In the lab manual you will find detailed instructions for constructing the pizza box spectroscopes, calibrating the instrument, and some experiments you can do with them.

In my class, I used my double block (80 minutes) to construct and calibrate the boxes.  This was sufficient time for most of my student groups to finish this part of the project.  On the second and third days ( both 45 minutes-long classes)  students used the spectroscope to measure the lines in the hydrogen spectrum, and then they identified several unknown elements and a mixture of two elements.  I even gave a lab practical question on the unit test in which they had to measure two lines on a spectrum.  They were graded on the accuracy of their measurements because I knew how good their boxes were working from their lab data.
These students are tracing my template onto their pizza box.
I decided not to give out any written instructions for constructing the spectroscopes.  To get them started, I made a pizza box template which student groups copied onto their own boxes.  I put out my spectroscope as a model (yes, I'm that proud of it!) so they could see how it's supposed to look when constructed.  Once the template was traced onto their own box, the lab groups used a box cutter to cut out holes for the diffraction grating and the light slit.  The funny part about the whole project was watching kids figure out how to fold a pizza box.  It's not as easy as the pizza guys make it look!
Once the template is drawn, students use box cutters to cut out the eye hole and slit hole.

These students are taking photos of the whole process for their lab report.
Once the box was constructed, the students fastened their diffraction grating to the front and two razor blades (to make a narrow slit of light entering the box) at the back.  They fed the pre-marked plastic rod into the holes and then closed up the whole thing with metal tape.  The metal tape was important because it helps to minimize the light "noise" coming into the spectroscope.  The tape also gives the boxes a modern, sci-fi-ish look that all found very aesthetically pleasing.  We figured out that inserting the rod BEFORE closing up the box was critical because the rods are very difficult to feed through the holes of the box when it's closed up.

The metal tape is important to seal off gaps to avoid stray light from entering the box.
I didn't think much about the size of the pizza boxes, but it tuns out that the ones I got from our local pizza place were slightly larger than last year.  (Thank you Pizza 101 for donating the pizza boxes for the project!)  This only became I problem when I realized that my plastic rods were too short!  The end of the rod disappeared into the box when we tried to measure the red light.  I quickly figured out that 1.5 feet of plastic rod for each group was not going to be enough for all three classes.  As fate would have it, our head of school called a "head master holiday" on the second day of the project.  This meant that one of my classes missed the double block, and thus did not get to make their own pizza box spectroscopes.  I was saved!  These kids learned how to use the boxes from last year (so I glad I saved a few) and still got the full experience of calibrating and measuring with a pizza box.  I'll order more plastic rod for next year.
It's hard to limit the light "noise" from the holes for the plastic rod.
The diffractions gratings that Edmund recommended for this project are from a company called  Although they were slightly more expensive than others, Edmund emphasized the importance of this part of the box and how much he liked these particular diffraction gratings.  Although there is an initial cost to purchase the diffraction gratings, I can use them every year to make new boxes.   I decided to throw out the old razor blades when I deconstructed the old boxes because they rusted over the summer and it seemed like a bigger hazard to get a cut by a rusty razor blade.
Putting the finishing touches on the box to minimize stray light and make it look cool.
The spectroscopes were ready for calibration by the end of the double block.  I have written a separate post about calibrating and using the spectroscopes.  

Saturday, May 2, 2015

NEACT May Meeting

Leslie Bishop introducing the meeting.
Lesley Bishop hosted the meeting at Regis College.  The focus of the meeting is technology applications in chemistry.  The two speakers on the schedule today are Mary Christian Madden and Erin McQuaid.

Mary Christian Madden was up first this morning to share on-line resources she uses in her QVCC chemistry course.  Mary comes to us with forty years of experience in education including high school teaching, principle in a high school, and now teaching at Quinnebaug Valley Community College.

The first resource she shared is from the Anneberg Learner website.  It's a complete on-line and free chemistry course with a text book, videos, links, and interactive simulations.  This resource is an excellent source of
Annenberg Learner Chemistry Course

MIT has a collection of chemistry videos that are produced by the professors at the college.  This video project was developed to help engage students in chemistry applications and feed the real-world applications that keep students interested in learning chemistry.  We watched a video from an MIT professor who has meet great success as a biochemist, even though she meet great challenges as a student because of severe dyslexia.  This site is searchable for short videos related to a wide range of chemistry topics.
MIT 2-minute Chemistry Video Collection

Every chemistry teacher out there needs to play around with PhET simulations.  Nearly everyone in the room is using PhET and has some comments to add to the discussion about use and implementation.  One issue that was raised about using PhET is the need to download Java onto school machines.  A close working relationship with the IT folks at your school is a must!  You can read about my use of PhET on my previous post.  Phet is Phabulous
PhET Simulations

A student in Mary’s class found this resource while reviewing for the final exam and passed it along to Mary.  Free text book, downloadable.  She makes this free download available in the library with a thumb drive they can check out.
Chem1 Virtual Textbook

This resource is a download or hard copy book that you can purchase through the internet.  Mary purchased the download to make it available as an additional resource to her students, while it was still free.  It is now available at a cost, which you can find out about at the link.  This resource is focused on drill and practice of chemistry problems.  Students get immediate feedback about their work because the answers are given as soon as each problem is completed.
Calculations in Chemistry on-line Tutorial

Mary recommends Khan Academy to her students for more practice and review of concepts.
Khan Academy Chemistry

Before coming out for the meeting, Mary gave her students at QVCC a survey to find out what links they are using to supplement their course content.  Here are the most frequently used sites:
Khan Academy and  YouTube.  She found out that many of the students didn't look at the resources that she listed on the course web page because they aren't as easy Khan and YouTube.  Some of here students don't use any on-line resources because they don't have any extra time to follow up on it.  Some discussion followed about how to introduce on-line resources and simulations to maximize the learning outcomes.

Nova:  Hunt for the Elements is a video or an app for the iPad.  You can use video clips to supplement a lesson.  The whole video is very long, so probably not a good assignment for students to digest all at once.

Our second presenter was Erin McQuaid, a teacher at Regis College.  She teaches a chemistry course for nursing students in the BA program.  She recently converted her class to flipped learning model, taking advantage of training and resources available at Regis to learn how to make videos and use on-line resources in her class.  Regis is in the third year of iPad integration campus-wide.
Erin gave a great presentation, even though her iPad wouldn't cooperate.  

Erin gave us a description of the changes in her teaching over the past twenty years.  She started with an overhead project and markers in the back of the classroom, teaching with the lights dimmed and watching her students take notes.  Now she can teach her lesson with her stylus and iPad from anywhere in the room using smaller tools.  She teaches an intense course that includes general chemistry, organic chemistry, and biochemistry all in one semester.  The volume of content in the course lends itself perfectly to the flipped lecture style.

Erin started off making her videos on Educreations (it was free at that time).  This resource was her video recording app of choice because it was easy to share the videos with her students.  When she polled her students about how they liked using the videos, she got a 50-50 response.  Ironically, the younger students didn't like the videos, but the adult learners appreciated the videos much more.  They really liked having the flexibility to watch the videos on their own time when they could fit it into their schedule.  Now that Educreations is not free, Erin has changed to bcontext, which is not free but less expensive than Educreations.  With bcontext, you can record videos on iPad and add in pictures and images into the video.

Erin uses the videos for homework assignments and she incorporates them into the long evening classes.  For a portion of the two hour lecture, she gives the class a break to watch a video and then the reconvene to do practical applications of the video as a class.  She also relies on the video lectures to make up for missed classes on snow storm days (which we had several this winter!).

Some resources for game/quiz apps: or  Both of these apps have pre-made quizzes available, but you have to review the questions and answers to make sure they are correct and what you want.  Erin highly recommends the app Noteablility for electronic notebooks, allows students to incorporate Erin's lecture notes with their own notes and other images or audio notes all in one place.  Another app Erin recommends is called Molecules, which presents molecules three dimensionally.