MU Chemistry Modeling Workshop: Day 1

By | July 11, 2011

I’m just starting my second week of a chemistry modeling workshop. While I’ve been furiously taking notes, it’s taken awhile to transfer it to my blog. So over the remainder of the workshop, I’ll post about my experience, and give you an idea of what the modeling workshop is like. If you find this interesting, I strongly encourage you to sign up for a modeling workshop. It’s a large time investment, but some things you can only really observe and experience in context.

Day 1

Pre-Test

After introductions, we took an ABCC (Assessment of Basic Chemistry Concepts), which is similar to the Force Concepts Inventory used for modeling physics and the Chemical Concepts Inventory published in the Journal of Chemistry Education. Students are typically given this pre-test on the first day or two, and will retake it after at the end of the year. We will retake it on the last day of the workshop.

Modeling Rationale

Next, we viewed a powerpoint on what modeling instruction is, and why it is effective. Most of you reading this blog tend to agree that the transmission model of education isn’t particularly effective or desirable when it comes to student understanding. Modeling asks students to construct and use scientific models (diagrammatic, graphical, algebraic) to describe, explain, and predict phenomena. Models are evaluated not against a textbook/reference standard, but by a comparison with empirical data, ideally collected by students. I’ve embedded the presentation here:

Eureka/Ring of Truth

The modeling curriculum encourages the use of certain videos to introduce topics, or help students move ideas along in their minds. One particular series, Eureka, is used to introduce the first lab on mass. I managed to find this video on YouTube:

The videos have a bit too much anthropomorphizing for my taste, but it does help to explain somewhat abstract ideas in a relatively short chunk of time. The other series used frequently in the curriculum is Ring of Truth by Professor Philip Morrison. The particular clip we observe here is on conservation of mass, and shows the effect of a quite elaborate series of physical and chemical processes on the mass of a closed container. Its fun to watch!

Mass & Change Lab

The Mass & Change Lab is a relatively simple activity for students to observe and describe the relationship between the mass of a substance before and after it undergoes some type of visible change. In the first investigation students determine the mass of a piece of steel wool, and then stretch it out, and determine the mass of the new, expanded steel wool. Students can predict whether they expect the mass to increase, decrease, or stay the same, and then test it. Most students will predict that the mass will stay the same, but for nearly all the mass will decrease. (due to small pieces falling off when you stretch the steel wool). In the follow-up discussion, you can have a discussion about lab technique and observations, and ask how they might modify the procedure to ensure that the breaking steel wool will be massed as well.

Next, you discuss the next 5 investigations with students, and devise a procedure to test each. The investigations are

2) Melting ice
3) Burning steel wool
4) Dissolving sugar in water
5) Formation of a solid when two clear liquids are mixed
6) Dissolving Alka-Seltzer in water

Students also make predictions about what will happen beforehand (clickers/polleverywhere?), then perform the tests.

After the lab is complete, students split into 6 groups and on large whiteboards draw a diagram to describe what happens for one process on the smallest level. During the “Board Meeting,” students tease out a particulate-description of matter, and relate their particle models to the observed mass change. The emphasis of the discussion is how the diagram demonstrates a mass change, and what happens when mass change does occur. Specific terminology (precipitate, combustion, carbon dioxide) can be avoided here, as the main purpose of the activity is to conceptualize the idea of mass conservation.

After this discussion, students complete WS 1, which revisits the lab investigations, and checks for understanding of the underlying concept.

I really like this activity. It is very simple, and uses very common materials that most students have some experience with. It is also important for students to make the leap early on from a continuous view of matter to a particulate view.

Volume Lab

After defining mass as “stuff,” we begin to look at volume as an amount of space. In this lab, we compare the calculated volume of water in a vessel of some simple geometric shape to the measured volume in a graduated cylinder. Students look at 5 different volumes, and plot the measured volume vs. The calculated volume.

I love this activity because

  • it’s very easy (though teenagers + water tend to make a little mess)
  • students tend to take conversions (1 mL = 1 cm3)for granted. Here, we can demonstrate, with real data, why this relationship is true
  • when asked to make an equation for a line describing the relationship between measured volume and calculated volume, students actually plug in the variables used in this experiment (not a generic y = .999x + 2, but measured volume = .999 * calculated volume + 2)
  • you can have a real discussion about the meaning of the y-intercept (what does it physically mean? Does it make sense in this case? When is it okay to disregard it?)
  • you can discuss what slope means. Not a generic calculation of slope (rise over run) but a verbal description of the relationship between the variables being studied.
  • you can discuss uncertainty in measurement (why isn’t the slope = 1? Why aren’t all groups slopes the same? Are they close enough to 1 to say that it should be 1?)

While the lab is technically simplistic, these discussions will be very useful when applied to more complex concepts (density –> gas laws –> ??)

Homework

For homework, we read an article by Bruce Alberts (Restoring Science to Science Education)


7 Comments

Scott Thomas on July 11, 2011 at 10:02 pm.

Great to begin to see your experience. One of our instructors briefly mentioned the Eureka videos. As a physics teacher, I don’t think I would ever show them. To me saying mass is “lazy” could possibly infer that something else isn’t. Anyway, I used to teach chem and it’s very interesting to see how the modeling is adapted for that subject. I’ll be sure to send my school’s chem teachers this way!

Reply

Ms. Bethea on July 11, 2011 at 10:26 pm.

I’m on the fence about whether I will use the Eureka videos. I think they can contribute to misconceptions about how particles interact with one another. The reason our instructor uses it is that she would prefer that direct instruction (basic information/descriptions/definitions) come from a video than from her (“sage on the stage”). I wonder if there might be other videos, simulations, or animations that can accomplish the same goal.

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Tracie on July 11, 2011 at 10:17 pm.

Good for you! I took my first Modeling workshop last year and am totally convinced.

My kids did the first part of Lab 1 four times before we got data good enough to draw any conclusions. They had never had truly use data from their labs before and couldn’t believe that I actually expected them to learn from the lab.

Good luck and keep us posted!

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ryan mcclintock on July 12, 2011 at 12:20 am.

Thank you for reviewing the workshop in such detail.

Are the “board meetings” as simple as groups sharing their models to the whole class? Is Q&A common from teacher and students?

Are groups devising plans to investigate 2-5 or is this done as a class?

I know the answer to these questions can be, “Well, it depends,” but I’m wondering what was recommended to you at the workshop.

I like the idea behind the volume lab for many of the same reasons you described … Any opportunity to discuss slope.

Anyway, thanks again for reflecting in such detail.

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Ms. Bethea on July 12, 2011 at 12:55 am.

Yes, board meetings are that simple. How it is conducted may depend on the physical space of your classroom. Ideally, it would be best to get the class in a circle, but that is physically impossible in my classroom.

This early on, the questions are primarily from the instructor, but beginning in Unit 2 questions are solicited from students (will discuss later). I really do suggest watching a modeling teacher or attending a workshop, as its hard to describe in writing. But the questioning is very intentional, and focused on the underlying model and concepts, emphasizing and reinforcing the connection between macroscopic/microscopic/symbolic representations and building on that model where needed.

As for Mass & Change, it was recommended that the procedures are created as a class for 2-5.

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Ryan McClintock on July 12, 2011 at 11:39 am.

I look forward to attending a workshop.

I was just recently introduced to Modeling Instruction primarily through @fnoschese’s Khan and Flipclass tweets and blogs. I looked into workshops, but working one into this summer wasn’t possible … so for now, I am thankful for the resources you and others have lead me to.

Oh, I think your idea to meet up with a local modeling teacher is a good one!

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Dawn Johnson on July 11, 2013 at 11:59 am.

Thank you for posting your thoughts in great detail. I just finished a two week modeling workshop and while I took copious notes (scribbling like MAD!) what you’ve posted on your blog will be a wonderful cross check and reference.

I’m diving in with both feet this year and am delighted to have found your blog!

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