Friday, September 30, 2016

Sorting out the Atomic Model

Discussing the Plum Pudding model.
I am a big fan of sorting activities to help my students learn new concepts. I have several "card games" I use for nomenclature and for writing chemical formulas.  I also have a set of cards for identifying chemical and physical change and chemical and physical properties. I like to use the sorting games to help teach new concepts or to practice difficult skills like naming acids. The article "Learning By Sorting" by Michael Lovrencic and Laurie Vena in The Science Teacher, Feb. 2014 gives a nice explanation of the technique.

This year I decided to add a sorting activity for the development of the atomic model to my repertoire. The traditional atomic model lesson boils down to a vocabulary-heavy history lesson. Even with a demonstration of the cathode ray tube and a Phet simulation on the gold foil experiment, it is hard for students to understand the important points of the story. In an effort to make this lesson more student-centered, I've moved the content delivery portion to a homework video the night before they do the sorting activity. In class, I placed pictures of the five atomic models around the room. Each student received a set of two or three cards with terms, phrases, or names that relate to one of the models. The first challenge was for each student to identify the model that fits their set of cards. Once they have gathered around the model, the students then had to work in a group to sort their cards and generate an explanation of the words, phrases, and names on the cards for their model. I gave the groups about fifteen minutes to discuss their model and make a plan for their presentation. Each group gave their explanation of the atomic model to the whole class, starting with Dalton and working in chronological order through the Plum Pudding model, the nuclear model, the Bohr model, and finally the quantum model. After each group presented to the class I showed the kids the cathode ray tube and then we worked with the Rutherford Scattering PhET simulation. The final event of the day was a review of the information. I presented each small group with a full set of the atomic model cards to sort. Although they knew the ones from their presentation, they needed this chance to think through the other important discoveries and scientists associated with the whole picture.
The full set of cards for the Atomic Model Sorting Activity

I was pleased with outcome of this sorting lesson: shifting the learning into my students hands with the card sorting and the class presentation. I think that with a more interactive lesson the atomic model was more accessible to my students. The small group activity generated thoughtful discussions as they tried to piece together the facts and explain the experiments that led to new discoveries.

Presenting the Bohr model to the class as another step in the atomic model.

The nuclear atom resulted from Rutherford's famous gold foil experiment.

It's hard for kids to believe that The Plum Pudding model was the best explanation at that point in history.

Dalton's atomic model didn't really come with a picture of the atom, I had to ad-lib a little.

The quantum model of the atom proved to be difficult to draw. I captured the strangeness of it in this picture.

The extra large white boards are great for sorting activities. Here are the physical/chemical change/properties cards.

White board humor during a metals and non-metals sorting activity.

I am happy to share the templates for my card sets. Please email me directly if interested at

Monday, September 19, 2016

I'm in Love with the Excel iPad App

A student works on the Excel iPad app to plot lab data.
That seems like an extreme position to take about a mobile app, but the Excel iPad app stole my heart this week. It was the third and final stop in my journey to plot lab data and generate a linear trendline. I'm probably not going to touch Google sheets or Numbers with my students for a while.

Last Tuesday I had my students do a two part density lab. I had three goals in mind when I planned this lab: learn how to take good measurements, use significant figures from lab data in a calculation, and make a calibration curve using a spreadsheet. The third part of this goal statement occupied most of my attention this week.

Google Sheets makes nice data charts, can do calculations, but no graphs. So annoying.

I started the first block of lab day the way I usually do: make a google sheet, rename it, share it with your lab partner and me. I love the share feature in the Google products. The kids all loaded the Google Sheets app on their iPads before the lab, so what could go wrong? Everything was going along just fine until we realized that the moblie app for Sheets does not make graphs. What?! How could Google do this to me? Why make a spreadsheet if you can't generate a graph?!

Numbers allows for sharing in the new iOS-10, but no trendline for the graph. Grrrr.

My backup plan was to transfer the data to Numbers. This is an Apple product that is designed to work well with iPads and other Apple devices. And to my delight, the new iOS-10 update enabled a share feature in Numbers just like Google Sheets. Hurray, my problems were solved. The iOS-10 update started on Tuesday and took another day for everyone to complete, so we lost another day in the journey to good graphs. By Wednesday we were ready to transferthe data over to Numbers where the kids were able to share the spreadsheet with each other and with me. This was looking very promising. We plotted the data to generate an x-y scatter plot, hurray, but Numbers does not plot a trendline. Ugh. Why? The class ended without a full analysis of the data.

The Excel App allows for all the functions of a full spreadsheet program, but no sharing.

On day three of this lab analysis journey I asked my students to download the Excel app to their iPads and transfer their data into a third spreadsheet program. I begged for their patience with me as I learned what tools to use for the tasks have to accomplish. They were good sports about the transition to Excel, especially when they got very nice graphs with a trendline and an equation without much fuss. I am so grateful Hans Mundahl for making the YouTube video that saved the day. Graphing in Free Excel App for iPad with Trend Line & R Value (No Office 365 Subscription Needed!) His short video was the key to success with this excel app because he showed me the hidden trendline with equation graph format in the charts menu. With the fx format our graphs came out very nice. The Excel app is very much like the full program I use on my computer. Working on the app felt very comfortable and we were able to get the answers we wanted from our data analysis. My only complaint is that I can't use the share feature with Excel like I can with Sheets or Numbers. In the end I prefer the robust features available in Excel over Sheets and Numbers, and I'll just have to live without real-time sharing. Unfortunately, this story doesn't have a completely happy ending. I showed my students how to submit their Excel workbooks to iTunesU which seemed very easy and convenient. However, the graphs did not make journey unharmed. When I opened them up to grade their work using our iTunesU class, the graphs had turned into a sad mess. Every small step forward requires a lot of tinkering and sometimes includes steps backwards. The iPad transition continues...

Saturday, September 10, 2016

My First Week at Woodstock Academy

I love my new school! And take a look at my chemistry team! The picture says it all. Caroline and Mel are enthusiastic about everything and so much fun to be around. These two women have helped me with everything from finding the coffee to taking attendance. They have helped me figure out all those little things that you just know how to do at work, with a huge amount of patience and kindness.
The chemistry team at Woodstock Academy! 
I suggested that we do the classic copper and nitric acid demo on the first day as an exciting introduction to chemistry. Caroline jumped on the idea and decided to do it with her classes too. I've done this demo many times without a hitch, so we decided not to try it out before class. Doesn't this sound like the start of every failed demo story? 

We started the demo on the bench, just like I've always done before...
Caroline and I set the demo up on the lab bench for her A-block class first thing on the first day of school. We decided to do it together the first time through so she could learn how to do the demo. We got the apparatus set up and made the basic solution for bubbling of the brown gas. The first problem we noticed was that the reaction was going too slow. We had the wrong concentration of nitric acid. This demo requires concentrated nitric acid to work. I ran back to the acid cabinet and found the big bottle with the partially corroded label. "Let's try this one, it smoked when I took off the lid. It must be the right stuff."  Caroline added the concentrated to the reaction flask causing a vigorous reaction to start right away. Check, this is the strong stuff.

Right away I noticed a big problem: the brown gas started leaking out of the flask rather than bubbling through the solution in the graduated cylinder. We made the decision to relocate the whole thing to the fume hood. Working together, Caroline and I picked up the whole set-up and moved it to one of the hoods, where we conducted the reaction for the rest of the day.

We decided to move to the fume hood when the brown gas started leaking out of the flask.
We quickly realized that the tube was clogged. Caroline decided to prep another round bottom flask to run the demo again, meanwhile I cleaned out the tube. Note to self, check the tube next time! (This never happened before, so I didn't think to check the tube.) Our second run worked great and the kids were excited to see the penny react to form many beautiful colors. At the end of the day the three of us had a good long laugh about the crazy start to the day, and our total commitment to making the reaction work.

The view from inside the fume hood.
Taking a photo of the demo with iPad for the write-up.
Woodstock Academy is a one-to-one iPad school. Much of my week was spent figuring out how to do all the things I used to do during class with my computer from my new iPad. I made frequent visits to the tech office to tackle technology questions every day this first week. The guys in the office showed great patience with me as I worked through all the stages of the iPad transition. They were also extremely helpful with the adoption of my iBook this year. Getting the iBook ordered and on everyone's iPads turned out to be quite a journey. I learned all about the business office, the tech office, iBooks, Apple's ordering system, and more.

First Day selfie of my A block class.
The best part about my week was getting to know my students. These delightful young people are curious and eager to learn.
My D-block class, minus many of the international kids who arrived late.
My enthusiastic C-Block class, not shy even on day one.

I started the kids on a lab design activity on the first day. They jumped right into the first experiment in which they designed their own procedure to isolate and measure the mass percent of mixture of sand, salt, and water.

We jumped right into a group activity to design an original experiment.
Before we started doing lab work the kids went on a lab equipment scavenger hunt. They had to go through the lab looking in drawers and cabinets to find lab items they will use this year. It was a hunt for me too because this was the first time I had a minute to look around the lab myself. I couldn't give them much help finding things because I was still learning the locations myself. In the first block no one could find the first aid kit. By the third block of the day of the scavenger hunt we located it in the cabinet by the door. B-block had a good laugh when we found the faux cabinets at the top of the lab that don't open. No chance I could use them anyway because they are way too high to be useful to a short person like me. Several times I exclaimed things like, "Hey, we have a whole set of condensers." I was very excited to find a cabinet full of 1000 mL graduated cylinders, my favorite lab glassware.

Fake cabinets? We found these during the scavenger hunt.

It was a scavenger hunt for me too! This was my first look into most of the cabinets.
Separating and massing a mixture of sand, salt, and iron.
It felt good to get into the lab with my students on Wednesday this week. Being in the lab is where I do my best work with students. I enjoyed watching them work through the separation steps and consider the purity of their samples as they worked. We ran out of time for the last step so we put the salt water in the drying oven overnight. In the morning we were greeted by beautiful salt crystals. They were so gorgeous that some of my kids were inspired to enter the Nation Crystal Growing Competition that starts in October. (more to come about that later)

I couldn't resist a first lab day selfie.
Serious about evaporating off the water to recover his salt.

These beautiful salt crystals formed overnight in the drying oven.

I ended the week with a fun demonstration of the distillation of cherry coke. The result of the simple distillation also surprises the students. The strong smell of the cherry flavoring in the first fraction is impressive. This demo finished off our discussion of separation techniques and gave us a good platform for discussing physical properties.
Demonstrating distillation with cherry coke.
It took my several days to figure out how to get coffee.
Starting a new job is exhausting! I sighed with relief at the end of each day this week. I'm still figuring out the daily schedule, the layout of the building, and many other day-to-day things that everyone else knows. It took me until Wednesday to find the Keurig machine in the faculty room. But just as I was celebrating this small victory, I discovered that the machine doesn't work. I was on the verge of giving up on coffee altogether for that day, but Mel and Caroline encouraged me to go down to the cafeteria to use the good Keurig. Getting that cup of coffee felt like a huge accomplishment on Wednesday morning. Friday afternoon came and I was completely spent from the four-day work week. When I got home my dear husband asked me out for dinner to try a new place in town. Much to my delight, three of my adorable new chemistry students were working at the restaurant. It feels good to be more integrated into the community with this new teaching position. After a good nights sleep and a morning with my spinning guild, I feel refreshed and ready to jump into week two.

This interesting mushroom family was growing right by the parking lot exit.