HS PS 1-1 Lesson Progressions Part 1

If you're a regular reader, you know that this is our first year of full implementation of NGSS, and although I am thoroughly convinced we're doing it right, we are still working out the kinks. Of course there was a little insecurity of our students through unit one, and when it came time to review for the test they were really freaking out. They didn't feel that they had a strong set of notes or resources to refer to while studying. Throughout the unit, I really had to reassure them that they were doing well and that a new style of learning is something that everyone has to get use to, but in the end they're going to grow significantly as a science student. I took these insecurities as great feedback to help us better support them while continuing to keep the philosophy of NGSS very much in the forefront of our planning for Unit 2. After all of the details were worked out on the progressions we would take for this unit, I decided to make a guiding document for the kids to use through the unit. We were a little hesitant about doing this, as NGSS really wants students to guide the learning, but it worked out great. Through this lesson progression blog for HS PS 1-1, I'll also show you how this looked in the guiding document. We chose to call this an anchor guide because our departments K-12 are in the process of creating anchor charts for each unit, so our goal is to make sure these are parallel with each other so that it is very cohesive for the students.

HS PS 1-1 was a pretty big section of unit two, so I'm actually going to break this down into two different blogs. 

So here we go!

To start off, we made the simple adjustment of changing the performance expectation into an "I can" statement. So at the top of the anchor guide, it says:


Performance Expectation:
I can use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.

LP 1: Phenomenon Reactivity of Metals
We chose to show the metals, lithium, sodium, and potassium in water. In years past, I've allowed students to do this themselves with no problem. This year we chose to show videos of the reactions. We will come back and let them do this themselves with VERY small pieces when we get into reactions, but for now we really wanted them to be controlled and see consistent results. After showing each video, the students wrote their observations down in their anchor guide:

Observations
Lithium
Sodium
Potassium




LP 2: Asking Questions about the Phenomenon
After watching the three videos, the students asked questions about the reactions. They did this part individually. We spent a lot of time developing quality questions during unit 1 (you can see how we did this in my previous post), so their questions were much more developed. The day before we presented this lesson, we had a session with Paul Andersen about linking questions to the CCCs, so I was able to immediately adjust this questioning activity to reflect that. Here's what this looked like in the anchor chart:

Asking Questions:
What questions do you have about the phenomenon?

Question:
This question relates to… (circle one)
1

Patterns
Causes
Systems
2

Patterns
Causes
Systems
3

Patterns
Causes
Systems
4

Patterns
Causes
Systems

After they finished writing their questions, we spent some time talking about the CCCs. Last unit we very carefully introduced each SEP, so this was a perfect place to introduce this third dimension. I took the literature from the NGSS Appendix that explains the purpose of CCCs and made it into more student-friendly language. You can view this document here. 

Once we read through this and had a clearer understanding of these categories of CCCs, the students chose which category their questions fit into. I then had them choose one question to share on the board. 

They each took a small whiteboard and we randomly selected questions that were written on the large whiteboard. I asked them to determine which category the question would fit into. I'll give you an example so you can see how this would look:

Question on the board: "How does the molecular structure of each metal explain the reasoning behind their reaction with water?"

Student responses: a few "patterns", several "causes", and no "systems"

I then asked whose question this was. The student raised his hand and told us that he determined that this was a structure question. I asked him why and he explained. This led into a discussion of whether or not just because others thought it was a patterns question they were wrong. In the end, I really wanted them to understand that questions can really fit into any of the three categories because they're so connected to one another. When we choose ourselves where we think the question belongs, it helps us determine what we are going to investigate next. Are we going to investigate the patterns we see structure, or are we going to investigate how the structure causes the function? Either investigation would be valid, but knowing which CCC it fits into for us as the scientist will guide our investigations to be more focused. 

LP3: Develop a model to explain the phenomenon
After this discussion, I had the students choose a question that they wrote down and model it in their guide. This was different from last unit, as we were all modeling the same thing. This time they were all choosing different aspects to model, but essentially we were all trying to figure out the same thing. This is what this looked like in the guide:

Developing Models:
Develop a model to answer one of the questions you’ve formulated above. Before you begin, make sure you have written quality questions.

Make sure your model has all of the components we’ve discussed that good models have.

This was the end of the first class period of this unit. When they came into the next class, I had them pair up with a table partner and explain their models to each other and give feedback, then make any revisions they saw necessary before moving on to the next lesson progression.

LP4: Analyze various sets of data to determine structure of atoms and trends on the periodic table.

This next part of the unit is very heavily taken from the AMTA modeling curriculum. I've recommended this training in previous posts, but I cannot say enough great things about it. It's one of the best professional developments I've ever had.

Here is what the anchor guide looked like for this part. Italicized green parts are my clarifications added for the purposes of the blog:

Analyzing & Interpreting Data:
1. Open the data provided on PowerSchool Learning. Graph this data on LoggerPro (If you don’t know how to operate LoggerPro, watch this tutorial video).
This data includes all of the ionizations energies of the first 20 elements, and the atomic radii of the same elements. The tutorial explains how to analyze data in LoggerPro. Our students are familiar with it, but don't really know how to analyze data with all of its glory at this point. Here's what the graphs look like when they finish:



2. Analyze the Data:
Common features (trends) found on all Graphs
Differences between the Graphs



3. Group the electrons for each element based on similar ionization energies and total up the number in each group. Rescale your y-axis to logarithmic by double-clicking anywhere on the graph and check the, “logarithmic” box.
Boron

Silicon

Calcium


I stopped everyone at this point to make sure we were all on the same page about the trends we saw in the data. In the graph, the students should see the jumps in energy at certain points, so they were grouping them accordingly.

4. Is there a maximum number of electrons that can fit in each group? If so, how many?

5. Plot graphs of successive ionization energies for a few more atoms on a new LoggerPro graph. Does the evidence support your answer to #4? If not, revise it to be true.

6. Construct a claim that is supported by evidence that explains the trend you see in this data.








7. In your own words, using the claim and evidence you’ve provided, explain what ionization energy is.







At this point, we stopped and discussed the data and their explanations. This isn't perfect yet and they'll come back and revise their explanations later when they have more information, but they at least have an idea of what ionization energy is. 

Evaluating Information:
Before moving on, read through the information on the Bohr model of the atom found here.

Using your data analysis and interpretation, draw a Bohr model for each of the elements we’ve investigated
Boron
Silicon
Calcium

Most students at this point know exactly how to draw Bohr Models, but I really stressed that they shouldn't be drawing these models from memorization or because someone told you 2 electrons go in the first energy level and 8 in the next. They should be drawing them from the evidence they got from the data. The reading on the Bohr model I took from the CK-12 textbooks and edited it to take out any pictures or clear explanations of how to draw Bohr models. They really had to design their model from the information provided from the text and the graph. If they just googled it, it's really doing them a disservice. 

At this point, the students were beginning to ask questions about why the elements electrons within the same energy level have varying levels of ionization energy. This really didn't sit well with them, which brought us to the next activity which I will share in my next blog in the next couple of days!

Thinking back to how I use to teach periodic trends, I can't blame my students for not finding a lot of interest in it. The fact that they're really asking why certain trends are appearing and what is causing them is evidence that when NGSS is implemented correctly, it really does teach our kids to think like scientists, and they crave to continue to discover their unknowns. 

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