ModChem Day 6: Heat Capacity

Talanquer Reading

The reading discussion focused on Johnstone’s Triangle. Chemistry education rarely gives opportunity to bring all three: Macroscopic, Submicroscopic, and Symbolic together. Yet, all three are (mostly) required for students to gain a deep understanding that we’re seek.

Image: https://www.researchgate.net/figure/Chemistry-Triangle-Model-Johnstone-1982_fig1_353781044

As educators, it is easy for us to move through between the different representations of Chemistry. For example, when we say iron, are we talking about iron in our lab, the atom, or the symbol Fe. Our students will have a harder time identifying which representation of iron to use as they are novice chemists. When I started at SHC, we were administering the FCI as a pre-post-test for 9th grade Physics. I had no idea there was a Chemistry version of that, which was referred to as the ABCC. We took a version of it at the beginning of this workshop, and I thought it was a fantastic way to measure their growth of learning. The conversation then went towards cell phone use at school and responsible use of technology. I did write flipping Physics in my notes, so I’ll have to explore that a bit to find out why I wrote it.

How does a straw work?

Today, I learned that I didn’t understand how a specific technology item worked. That item would be a straw. I figured you stuck the straw in liquid, sucked it in, and then delicious cold beverage. In class, I learned that it’s far more complicated and underappreciated. It’s an elegant way of looking at how air particles and water particles might interact with this piece of technology. I never looked at a straw as a study of particle motion, and here we were. I’m not sure exactly where it would fit, though I did look at the teacher’s notes. I’m not sure if students at this point would know the IFE-PVTn table or if this would come before then. If before the 3-part PVT lab, then I figure there might be more focus on the air particle motion rather than the water. Otherwise, I think students might make the mistake of thinking that water particles behave in the same way as air.

U3 Lab: Thermal Energy & Temperature

For the Eth & Temperature lab, we had a calorimeter, temperature probes, and varying things to measure. First time around was 50 g Warm Temp/50 g Room Temp water. Second, we used 50 g Warm Temp/100 g Room Temp water. Third time around we used 50 g Warm Temp/50 g Copper shots. We took the initial temp of each separately. Then we made a prediction of what the final temperature might be. Then poured and quickly started collecting the temperature of the combined mixture.

We put up each group’s data on a whiteboard. And instead of each group making a whiteboard, we created a collective one. We discussed each situation and then drew particle diagrams for each. This image is for Part 1 of the lab, and as a class, we decided it to be true that the Hot temp “gave a whooshie” to the cold temp in order for all the particles to be at the same temperature.

It was at this point that I ended up lost. Hopefully, we revisit this in Day 7 and maybe iron out some wrinkles in our understanding of heat capacity.

On the left most part of this data table, we calculated the change of temperature for copper and change of temperature for water. We saw that some groups had a greater temperature change for copper and some had a greater temperature change for water. What accounts for the differences we see? Which one heats up faster or slower? We determined that the copper material heated up faster, and that different materials havea. different rate of energy transfer. But how we got from the question to the conclusion…the map got lost somewhere along the way. This was how heat capacity was introduced. I thought I understood heat capacity, but it seems that I might have it backwards.

We ended our day with working on Unit 3 Worksheet 1. We worked on some heat transfer questions. Our lab group kept trying to use the heat transfer equation, Q = m · C · ΔT, but we had to be reminded that the students don’t know that. We had a quick discussion of whether or not we would introduce to our students. I probably won’t because I don’t want students memorizing equations. I want them to understand concepts.

ModChem Day 5

PVT Lab Part 3: Pressure-Temperature

Data Collection: There were 5 stations that each had a liquid in a container of varying temperatures. There was super hot all the way to super cold. We used the Vernier Gas Pressure Sensor and the Vernier Temperature Probe to collect the Pressure and Temperature data. Our data formed a linear like graph.

Our data collection of Part 3. We graphed it and made a linear fit.

We graphed it and then discussed what the y-intecept meant. We continued the discussion to get us to discuss what the x-intercept might be given our data. It was revealed that the x-intercept was the absolute zero if we’re using the Kelvin scale to get a direct relationship. The next conversation was about the relationships between each variable.

We talked about which variables had an inverse relationship and which ones had a direct relationship. From there we transferred our knowledge into table form. Then worked on Worksheet 3: PVTn Problems using the table format. I think I’m going to need to do more practice with using this way to solve problems. I also liked that it was pretty easy to see which numbers would go up and down. At this point, we don’t have the equation yet. Peeking ahead, I’m not sure we will?

ModChem Day 4: Pressure, Volume, and Particles in Motion

Wenning Article Discussion

Some takeaways from the group discussion of the article:

  • Ideally, whiteboarding groups should be in groups of 3. I was creating too big of groups for Chemistry. For Physics, I was creating groups of 3. I need to maybe get more materials so that I can accommodate groups of 3 for whiteboarding.
  • It seemed to be a general consensus that we ALL need more practice in Socratic dialogue. I for one would love to read more of a how to, or some sentence starters. I used to have a notebook or document or something where I would write down really great questions to ask students each unit. I have since then lost that artifact.
  • Not all students plan to be a chemist or major in chemistry. Our role is to teach critical thinking through the context of Chemistry.

U2 – Energy and Particles in Motion

New unit lab/demo. To open up the unit, we watched Mitch light a match, blow it out, and waited. Whenever the smell got to us, we raised our hands to show that we smelled the sulfur, and we kept our hands up. I thought I’d smell it first since we were so close to Mitch, but it looks like the back of the room were able to smell the burnt match first.

We discussed the demo of two different temperatures of water. The hot water had red food coloring and the cold water had blue food coloring. We discussed with our partners what we thought was happening. Then we had to go back and redraw our model that include particles and the conventions we had agreed to use. We talked about the particles were in motion, and so we needed to add whooshies. The hot water beaker should have particles with more whooshies than the cold water. It was important that the water particles and dye particles were both drawn. The convention was that the number of whooshies would also indicate a difference in temperature between the particles.

U2 WS1 – Particle Motion

The apparatus that showed a thermometer using water and isopropyl alcohol as the liquids.

It was not until our Board Meeting did I realize that I keep missing the point: particles. I did not draw any particles on our board. Rather, I focused on the process that Celsius used in creating the thermometer. The discussion kept going back to the particles. What are the particles doing as heat is applied? What are the particles doing when cooled down? The idea of Eth was also introduced. In student mode, I kind of see the writing on the wall. Am I going to be learning the equation to calculate Eth? We learned that heat (Eth) involves temperature AND mass.

Eureka Videos

We watched a series of videos about molecules in different states and the motion of particles. This is where it becomes reiterated that heat makes the particles move faster, making the movement less predictable. The evaporation and condensation of liquids has something to do with the particles colliding with each other, walls of test tube, etc. I’m thinking maybe these videos can be homework or look for the corresponding text in the book.

One of the takeaways was how to make a thermometer. I learned how Anders Celsius created the scale of O – 100. What I missed was the drawing of the particles expanding and condensing and that’s essentially the value of the thermometer. It’s able to quantify the hotness of something.

Lab: Volume-Pressure

In this lab, we connected a 20 cc syringe to a Vernier Gas Pressure Sensor.

Our original whiteboard. I drew our particles to have decreasing whooshies as our Volume got larger. We anticipated that this might be a student misconception that the particles move faster when the Volume is decreased. Our Board Discussion consensus was that the whooshies on the particles would represent the temperature of the particles (move faster). The particles itself would be moving at the same speed, but would have further to travel.

We collected data using the Gas Pressure Sensor from Vernier. Hooked up the machine to the LabQuest screen thing. Each data point was collected by getting the average over 10 seconds. We used a syringe connected to the Gas Pressure Sensor to manipulate the Volume. I like the proportional thinking that would go into this. As Volume doubled, Pressure ________.

We took our data from the sensor and put it into Graphical Analysis. Our first iteration of the Pressure-Volume graph got us a curve line. The 9th grade Physics students would say it’s an exponential line (because it’s curved). I’m not completely sold on the linearization (top graph) of the data so that we would get that P = 1/V.

I pretty much spent today writing down the questions both Mitch and Jae asked us while we were preparing our whiteboards. I aslo appreciated having Rich as a lab partner. I’m going to be so sad when we get split up next week to new seats. Even though I have been modeling with Physics for some time, I still struggle because I haven’t seen or thought about Chemistry content since 2004. That was the year I last took any Chemistry class, which was Organic Chemistry…in college.

ModChem Day 3: End of Unit 1

Hestenes Paper Discussion

This was my notes that resulted from the discussion. There was so much more that I missed because I couldn’t write/process fast enough!

Lab: Gases

There wasn’t much given in terms of how to do the lab. There was no write-up of the procedures to follow. Because it was one of the first tasks of the day and I’m not taking 5 other classes, I was able to follow. I wonder if I should give students a general thing that’s written down, project the setup on the screen, walk through the setup, and then allow them to figure it out. Luckily, my partner was able to remember what we were supposed to do. 

He had the beaker, test tube, and alka-seltzer on the scale. I just needed to fill ⅓ of the test tube up with water. So this would be the massbefore. To complete our apparatus, we needed the jar filled with water and the trough to be halfway full. It was very important that we clip the hose connected to the hole so that we wouldn’t spend our lab time cleaning up water. 

We covered the jar with a plexiglass square. Then flipped it over and put it into the trough over the hole. I slid the plexiglass square out from under the jar. I was not completely successful in making sure that all the water stayed in the jar and we ended up with a small air bubble at the top. Mitch assured us that it was negligible, but also to include that information if our data came up horrible. Rich was in charge of quickly covering up the test tube. I had the job of dropping the alka-seltzer into the test tube and then removing the clip so that the air could travel through the hose.

We collected the massafter by allowing the reaction to complete before removing the stopper and reading what it said on the scale. I feel that it was smart that we kept the beaker/test tube thing on the scale so that it could remind us to read the massafter. We collected the volume of CO2 by measuring the amount of water before and after the reaction. Our final density value was pretty close to the accepted value of CO2 gas. We started to discuss if dry ice which is CO2 (s) would have the same density as CO2 (g). Even though they’re made up of the same particles, would they have the same density? We were asked to draw a particle diagram of CO2(g) and CO2(s). If the substance changes states, would it still be the same particle? There was some discussion about making it an opportunity to use proportional reasoning for this moment. Otherwise, I might get students to draw 21 particles in 1 mL square and 1500 particles in 1 mL squares (like I did). The result was: when vaporizing something, it’s a space issue and not a separate substance issue.

Lab: How thick is this aluminum foil?

This was such an elegant way of going from macroscpic measurements to scientific notation because of how small an object is. It was an easy way to introduce scientific notation and how to remain consistent with SFs. I really liked that students had to find their own way to figure out the thickness of the aluminum foil. We decided that we could measure the length and width of foil, and then use the Volume formula to find out the thickness of foil. From the data collected, we discovered that foil had 2 different thickness. Actually, we were given two different kinds of foils. What might explain the difference? Could individual atoms be that large?

U1 WS5 – Relationships Between Units

Working on WS5, I couldn’t help but do the problem using dimensional analysis. I’m in love with the DA train I learned in high school. When I started using the tables to show my work, it reminded me of how we used to do x-t tables and students need to show the Δx and Δt and from there, they get their slope. It bothered us so much that there were no tables to show our work that I just went ahead and revised WS 5 to include tables. 

During the WB discussion, there was looking at the change across the equal sign (different units) instead of vertical (same units). I kind of like across the equal sign because it establishes the ratio, but I like the vertical–because of the mantra: What you do to one side, you do to the other.

ModChem Day 2: Sig Figs and Density

Scale Reading, Uncertainty, Sig Figs

We quickly reviewed the SigFig rules, but I definitely felt unsusre of myself. It may be how my students might feel. I keep forgetting which trailing zeros count and which don’t. I really like how my learning partner, Rich, showed me what would count as “significant.” When completing the Scale Reading and Uncertainty worksheet, I thought that there would be a definite answer for uncertainty. It wasn’t until someone commented on our lab technique to see the meniscus of the water better did I realize that the uncertainty value could be entirely personal.

Lab: Density Lab

Our data of mass-volume for the metal objects. We did not collect the data for volume in the same order we collected for mass. We ended up with a funky graph at first.

We collected data for the plastic objects in a different order when we recorded the mass and volume. This lead to a graph that did not make sense. It was only after we stared at our data for some time did we realize that we should have completed it the same order. If I do this in the classroom, I might number the objects somehow? Label them, but I want to refrain from adding another substance. Maybe I can engrave them with the help of the Engineering department.

The Density Lab was limited to two materials. I believe when we did it last year, the students had to figure out the density for a variety of cubes. Then, for the irregular shaped objects, we kind of told them what the item was. Students would just need to look up the density value. I was struggling with creating my graphs on Graphical Analysis.The graph itself was created, but I couldn’t get it to do the linear fit. It was only after I completed my graphs on Desmos did I realize it was because there was a user error. I was trying to use Manual Fit (which needs the Pro version), but I needed to use the Apply Curve Fit. 

Mitch talked about using the word equivalency when comparing the mass value to the volume value. Then he picked up another item and said that next item’s mass value is equivalent to its volume value. I did freak out and disagreed vehemently with him. I argued about it for a while (in my head). During lunch, I came to the conclusion that I actually liked it. Students struggled with the molar mass idea and could not understand how 1 mole oxygen is equivalent to approximately 16.00 g of oxygen. So now, I’ve decided I do like talking about how that item has equivalent values that doesn’t necessarily mean “equal to.” We whiteboard and had our discussion until about lunchtime. To me that means that would be may 1-2 class periods of the actual lab and then 1-2 class periods of whiteboard? We do not have the luxury of time, so I’m going to work on figuring out how to shorten the time it takes to do these activities. 

U1 WS3 – Density

We worked on U1 WS3 – Density problems. Working on the worksheet + whiteboard discussion took the rest of our afternoon. My group members introduced the pHet simulation of Density. I like it because it made it obvious that we had to get the whole object to be submerged. During the Whiteboarding I did bring up that I saw aluminum had a density > 1 g/mL and the question one of my students had about why their grandpa’s aluminum boat didn’t sink. The approach of asking whether or not the boat was a solid shape (like a cube or a ball) came up. Then we went over and ended the day here.

Modeling Chemistry Day 1

It’s Day 1 of the Modeling Chemistry Workshop here at the birthplace of the Modeling Instruction pedagogy! I am very excited to be on this journey. I’m going to complain once about the weather, and that’s it (I hope). We left San Francisco and it was maybe 67℉. It is a cool 103℉ here in Tempe, Arizona. My poor daughter is looking at me wondering if this is going to be our life now. We will appreciate the “hot” Bay Area weather when we get back!

I forgot what it was like to be a participant in a modeling workshop! I forgot the feeling of drinking from the firehose (and how much I actually do enjoy it).

Day 1: Let’s not be shy about blowing things up! I’m most nervous about 1) doing this demo 2) guiding the conversation. As long as Mitch and Jae keep making the objective of the Board Meetings clear, then I can figure out how to guide the class toward the takeaway. My partner had some questions about my representation of oxygen. I’m wondering how my students might represent oxygen in this case. I liked the question Mitch posed that would steer the conversation: How can we represent things that we can’t see? 

Once he asked that, it was suddenly more clear how this would be the beginning of the development of the model. 

Day 2: Mass Change

I really like how this lab already had students collecting quantitative data and that the class would share their data on a shared table. I think I might do something similar, but put it on a document since there is limited board space in 206. I wish I took a picture of everyone’s board representations. There were some representations of the burned steel wool where there was an entirely different particle, represented by a different marker color. My group drew this by adding a new particle to our drawing of the stretched out steel wool. 

I cannot remember why having the particulate model of changing it entirely would not be advised. For me, I figure it’s because the previous substances would be completely removed thus breaking our Conservation of Mass point. I hope it’s that? 

The notebook entry I had for this lab. I just really wanted to draw my 3D rectangular prism figure. But this is really the beginning to the discussion of precision and accuracy in experimental procedure. Then, it was also a way to introduce significant figures in measurements.
This is a picture of how our group used the ruler to measure the “inside” of the container. One of the group members, Peggy, always asks her students: Which side of the container are you pouring water into? We always look at right side left side, but not always inside and outside!

Day 3?: Volume & Volume lab- the development of the concept that cm3 = mL. Last year, students did not get the physical experience of seeing that cubic centimeters does translate to milliliters. We kind of just told them in our Density lab. I like this idea of students experiencing this truth for themselves. This also introduces the concepts of error analysis that doesn’t necessarily need to be “human error”…which is what I always seem to see in lab reports. In this case, our choice of material and substance (water) contributed to the values being slightly off. 

We used Graphical Analysis to graph our group’s data. We discussed what the slope means and why would the y-intercept would be -12.37 mL. Can we owe the graduated cylinder 12.37 mL of water?

Physics Day 20: I survived another year of teaching position graphs

It’s the end of the quarter, and I admittedly did not do a very good job of preparing myself mentally for what was to come today. I knew it was going to be a short period (65 minutes instead of our usual 75 minutes). It wasn’t until I was chatting with another teacher did I realize it was…position graph day. This meant that we were going to need an insane amount of post-its. I’m grateful that the team ordered the post-its beforehand. I just needed to cut them so that so that they would fit on our whiteboards.

With Block 5, I cancelled the Quick Quiz first to save 10 minutes. First, we had the students draw the position line, but with the positive arrow facing left. Then we had them do the motion maps with delta-t at 2s, 1s, and 0.5s. THEN we did the 90-degree rotation of the graph. I’m proud to say that the students all did it, with minimal post-its falling off. I think it went much easier because they all had the same data. So when the students looked around and saw that their boards didn’t look like the others, they received immediate feedback that theirs wasn’t going well.

Block 5 students did a fairly exceptional job of following directions and making sure their boards look great.

The slopes came out pretty well. The discussion towards what does the slope represent was perfect. The students were able to hit it out of the park. It definitely helped that they also covered slope-intercept form in Algebra last week. I think this year, the students were able to identify what y, m, x, and b all represent on a position graph in the quickest ever.

I’m not sure if I prefaced it to the students that I despise post-it day. They were all on excellent behavior—which resulted in a class full of students on task and asking genuine questions to gain a better understanding.

After teaching today, I ran into Mrs. F and we both agreed this is one of the hardest teaching days. Now, we’re thinking of getting shirts made for us to wear.

Day 15: Chemistry and Algebra

Looks like this week’s theme is: ALGEBRA

We were working on finding the average atomic mass of elements’ isotopes. This involved percentages, solving for one unknown…and solving for two unknowns. Most students were comfortable with percentages and solving for one unknown. Once we got to solving for two unknowns, we kind of gave up. There were a couple of students who tried really hard and looked at the textbook copy in the classroom, searched “how to solve two unknowns”, or used AI tools to solve the problem.

Challenge 1: How to deal with percentages. Students did not know that dealing with percentages meant that 8% = 0.08 = 8/100. Once we got over this, some continued on with the journey of solving for abundance of isotopes in a sample. Another one was 100% = 1 whole. We were having trouble understanding 100% of the pie is equal to 1 pie.

Challenge 2: Finding the average. One of the problems gave the masses and abundance of 5 isotopes. Titanium-46 through Titanium-50. They were supposed to calculate the average atomic mass of titanium. Instead of dividing by 100, students were dividing by 5 because they couldn’t not differentiate between the number of different isotopes from the number of occurrences. I started calling the masses “test scores” and the percent abundance “students”…and then it became easier to understand what the class average was. As soon as I said average atomic mass, the analogy was no longer understood.

Challenge 3: Finding two unknowns. One of the problems gave the average atomic mass, but did not give the abundance percentages. Instead, students were to find the abundance percentage. Students did not have the confidence to find it. There were a couple who were able to go back to work as soon as I said substitution method or find out what y is equal to. The majority of the students were able to work it out and apply it to the next problem when I solved the first problem of its kind. A few were very much confused from the start to finish.

Once they solved for Boron-10’s percentage, very few were still asking how to find Boron-11. After giving two options, students forgot where 1 = x + y came from.

Overall, it was a very arithmetically taxing day, but I didn’t think it was difficult. I admitted to the students that when I sat down to make the answer key for this worksheet, I didn’t really want to because I was being lazy. But in the end, the actual algorithm and steps to completing it weren’t hard, I just didn’t want to. I’m hoping that motivated them to think of algebra as easy and not something I want to do as opposed to something that is hard and only for smart people.

Exit Ticket Retake

Consistent with the theme, the exit ticket had some challenges as well. It wasn’t really hard mathematically, protons = atomic number, protons + neutrons = mass number, protons + electrons = 0, etc. Conceptually, it was new and they really needed another practice. I would like to somehow have students whiteboard some problems so that they think through it together.

Day 14: Physics and Algebra

Today was Day 1 of 4 of the Frosh Retreat. For Block 5, I had 6 students present for class, and everyone else was rostered to be at the retreat. I don’t actually know if anyone was absent, but I expected them to be at the retreat. Block 6 – everyone was present. This 4-day retreat makes lesson planning difficult because it’s also at the end of the grading period. It’s not ideal that the retreat happens at this time. Perhaps, it would be better at the beginning of the next grading period as opposed to the end of the grading period.

Today’s goal was to have students practice calculating next-x, current-x, velocity, or delta-t given the others. Mrs. Freudenberg’s preference is to isolate the variable given x = x0 + (velocity * delta-t). I like to plug all the numbers in THEN isolate the variable. I will allow the students to choose a method they like better. I personally do not like the isolating the variable given the equation first. HOWEVER, Mrs. Freudenberg does teach AP Physics, so perhaps her method translates to making it easy once students reach AP Physics.

In the past, students found this day to be easy and the application of all that we’ve learned in Pyret and Physics. Today, we found out that the students found this to be the peak of their frustration (AS A GROUP). There were individuals who found this to be easy, but as a group, students expressed their frustration at not finding this easy at the first go.

I will need to make some videos this week to help the students understand this better.

Chem Day 11: Periodic Table continued

I had big plans for Day 11. We spent most of the class completing the Periodic Table instead. We had to take some time to review the Lesson 8: What Comes Around, Goes Around that was assigned for homework. Student feedback was that it was repetitive. I said that it was supposed to be repetitive. One of the students said she noticed that what we ended up with became what we start with for the next step. Though the students recognized that we began and ended with copper, I’m not really sure that they understood that matter was not created or destroyed (which was the whole focus of the lesson). In looking ahead, they were supposed to understand that Copper solid + Nitric acid was supposed to result in Nitrogen dioxide, copper nitrate, and water. I’m not sure where or how they were supposed to recall all of those chemical formulae.

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After this, I went into teaching the periodic table. I’m not sure I agree with teaching the whole periodic table at once. Rather, I would have liked to take some time and go through each of the groups and learn through context. We found Periodic Table Lesson from Layers of Learning. We went through the main elements, annotated our periodic table, colored in the groups, and had students write down some pieces of information about each of the groups. The students seemed to like this activity, but I’m not sure they really knew what or why we were doing it. It’s taking 3-4 classes to learn that each Group has similar properties. One of the exit tickets would ask for an element similar to a named element, and they did not know to look within the same group for the correct answer.

The finished product of one of the students’ periodic tables.