# Day 85: Whiteboarding & Percent Yield

Physics: Whiteboarding

Students whiteboarded their answers to Friday’s questions. There were a few questions where students had some good discussion and connected some questions back to the lab where they’d mapped electric potential. I still need to work on getting students to talk to each other more than they talk to me.

Chemistry: Percent Yield

Students worked on some problems calculating percent yield. While they can do the calculations pretty easily, the concept seems pretty abstract to them. I need to find a good lab to make percent yield more concrete.

# Day 84: Electric Potential & Whiteboarding

Physics: Electric Potential vs. Gravitational Potential

Students worked on a worksheet from the Modeling Instruction curriculum that draws analogies between gravitational potential and electric potential. Several students commented that relating electric potential to something more tangible helped them make sense of what we’ve been doing. I also had a very good conversation with a student about how last trimester, she really liked how connected the mechanics topics were, but doesn’t have the same sense with electricity. This confirms that I need to keep working on my storyline for this trimester, but it was great to hear some of the metacognition the student was doing and I consider it a sign of a good class climate that a student was willing to have that conversation.

Chemistry: More Whiteboarding

Students used whiteboards to work through another stoichiometry problem. A lot of students left with much more confidence than they’d started the day with.

# Day 83: Electric Potential Difference & Whiteboarding

Physics: Electric Potential Difference

In the past, I’ve motivated the need for electric potential difference in addition to electric potential purely through analogies to gravitational potential energy. Today, I tried an extension of the Modeling Instruction lab to map electric potential. I had students measure the voltage along a line in their tray of water with the multimeter’s ground attached to the negative lead of the power supply, then repeat with the ground attached to the power supply’s positive lead and the ground held somewhere in the middle. In the discussion, students agreed that the change in voltage is more meaningful than the specific value.

Chemistry: Whiteboarding Problems

Students struggled with the stoich problems I left them yesterday, so we took some time to go through the first part of one. I tried to be very explicit and specific in bringing up previous labs or activities that used each skill, and that seemed to help students make connections. Students then continued the problem in small groups working on whiteboards. I need to do more whiteboarding problems in this class; the whiteboards really helped students function as a cohesive group, which is really not surprising.

# Day 82: Mapping Electric Potential & Stoich Practice

Physics: Mapping Electric Potential

Students used Plotly to make contour maps of the data they collected yesterday. I was out on a field trip, so students followed along with a video I made last year. Based on my sub’s report and what the students I ran into said, the video went much more smoothly than when I’ve tried to give live instruction since students could pause and rewind the video to make it go at their pace. Tomorrow, we’ll do some talking about the results.

Chemistry: Stoich Practice

I left students two stoich problems broken up to try and help them think conceptually about the process. According to my sub, students struggled with the problems. Tomorrow, I’m planning to spend a lot of class time discussing the problems.

# Day 81: Mapping Electric Potential & Stoich

Physics: Mapping Electric Potential

Students collected data for the Modeling Physics lab on mapping electric potential.

Chemistry: Stoich

Students finished the lab from Friday. The idea was to work through a stoichiometry problem, using nuts, bolts, and washers to represent atoms. My goal was to get students to think concretely about the process so that the math would make more sense. While students got closer to understanding the process, almost none of them saw the connection between their materials and the math they were doing. I need to re-work some of the questions and directions to explicitly prompt them to use the materials at key points. I also need to think about how I could have students use the manipulatives to answer the most frequent questions I got, so I can give them that nudge next time instead of focusing on the math.

# Day 79: Electric Field Lines & Energy in Reactions

Physics: Electric Field Lines

Students whiteboarded their answers to yesterday’s worksheet. The time we spent on vector addition diagrams with forces paid off as students were very successful adapting those to make sense of electric fields.

Chemistry: Energy in Reactions

We started with a “mini-lab” to give students some first-hand, tactile experience with endothermic and exothermic reactions. After that, I tried having them sketch bar charts for those reactions, but it was clear I hadn’t done enough to help them understand what energy is, let alone the different types of energy that will appear in a chemical reaction, so the bar charts ended up a confusing abstraction for most students. I need to rethink how I approach reaction types next time to give students a better foundation in energy.

# Day 78: Electric Field Lines & Energy in Reactions

Physics: Electric Fields

Students built off what they can see in the PhET Charges & Fields to develop the idea of what electric field lines represent. Students mostly got into trouble when they  thought their answers were too obvious and tried to come up with something more complicated.

Chemistry: Endothermic & Exothermic Reactions

To introduce endothermic and exothermic reactions, we broke the terms down and talked about other words with the “therm” root and what that says about what these new terms might mean. Students then did some reading about endothermic and exothermic reactions. While the textbook doesn’t emphasize the role of energy in these reactions, I tried to bring that out in the short discussion after the reading.

# Day 77: Board Meeting & Activity Series

Physics: Electric Fields Board Meeting

Students whiteboarded their graphs from yesterday’s electric fields simulation. I was really pleased with how quick students were to bring up Coulomb’s Law as a way to check if their relationships made sense. There was also some good discussion about why linearization is useful, where several groups shared their initial attempt to linearize using a purely inverse (rather than inverse-square) relationship between field strength and distance.

Chemistry: Activity Series

Students dropped four different metals into four different solutions to see how many times each metal reacted. They were able to rank the metals in a crude activity series, then we looked at how that activity series could explain which solutions each metal reacted with.

# Day 76: Electric Fields & Interpreting Reactions

Physics: Electric Fields

Students used PhET’s Charges and Fields sim to look at how the size of a charge and the distance from a charge impact the magnitude of an electric field. Tomorrow, we’ll get from their data to the equation for electric field strength and draw some parallels between electric fields and gravitational fields.

Chemistry: Interpreting Reaction Equations

Students worked on using chemical equations to determine which of the five reaction types was happening. I was really pleased by the way students started to talk about what is actually happening in the reaction, rather than just talking about the abstractions represented in the equation.