Waves

Day 158: Refraction & Solutions

/ Marta R. Stoeckel / Leave a comment

Physics: Refraction Problems

Students worked on some refraction problems, including a lot of ray diagrams. I also left out some refraction demos and asked students to try and come up with explanations for what they saw.

A fish tank with a sign that disappears when viewed from above
Stirring rod in water vs. vegetable oil

Chemistry: Solutions Reading

Students did some reading to introduce some vocabulary for chemical solutions. I’m trying to emphasize translating vocabulary from textbook language to everyday language, and my students are getting more comfortable with that.

Day 157: Refraction & Empirical Formula Lab

/ Marta R. Stoeckel / Leave a comment

Physics: Refraction

Students played with PhET’s Bending Light simulation to start building some ideas about refraction. I tried to keep the questions very broad and focused on conceptual understandings. Students really took advantage of all the tools available and made a lot of very detailed observations that would have been tough or impossible in a more traditional lab.

Bending Light

Chemistry: Empirical Formula Lab

Students worked on a lab that terrifies me (I once had a careless student singe his eyebrows), but gives really nice results. Students started with a sample of copper II oxide, then burned off the oxygen to get pure copper. They then used their initial and final mass to determine how much oxygen was in the original sample and find an empirical formula.

IMG_1886

So much fire!

Day 156: Mistakes Game & Speed Dating

/ Marta R. Stoeckel / Leave a comment

Physics: Mistakes Game

We played the mistakes game with ray diagrams for curved mirrors. Its been a while since we last did that, and a lot of students were excited to play.

IMG_1884

Chemistry: Speed Dating

We did some whiteboard speed dating with empirical formula problems. By the end of the hour, most students were feeling pretty confident. Just to solidify that confidence, we did a “practice pop quiz” where I put up a problem and had students work through it in quiz-like conditions, then went through the answer and had some conversation about the next steps for people who didn’t do well on that quiz.

Day 155: Ray Diagrams & Empirical Formulas

/ Marta R. Stoeckel / Leave a comment

Physics: Ray Diagrams

Students took their first stab at drawing ray diagrams for curved mirrors. A lot of students made liberal use of colored pencils to keep the different rays straight.

IMG_1881

Chemistry: Empirical Formulas

I introduced students to empirical formulas, focusing on them as a new layer to the percent composition work we started on Friday. Students were pretty successful with the new skill.

Day 154: Curved Mirror Equation & Percent Composition

/ Marta R. Stoeckel / Leave a comment

Physics: Curved Mirror Equation

Students collected a little more data from yesterday’s lab, then whiteboarded the results to get to the curved mirror equation. The graphs were not as consistent as with some labs, but students were still able to get where I wanted them to.

IMG_1876

Chemistry: Percent Composition

Last trimester, a lot of my students struggled what they knew about percents from their math classes to percent composition in chemistry. This tri, before giving any instruction, I asked students to  answer a few questions like “What percent of this class is male?” Giving students those questions, then asking them to talk about the process they used, got students to bring the math into the class themselves, which lead students to make sense of percent composition much more easily than last trimester.

Day 153: Focal Length & Whiteboarding

/ Marta R. Stoeckel / Leave a comment

Physics: Focal Length

Students started collecting data to produce a plot of image distance vs. object distance for a concave mirror. A lot of students were trying to complete the lab with the mirror, candle, and screen all in a single line, so tomorrow I’ll need to review the directions and give a little more time to collect data.

IMG_1871

Chemistry: Whiteboarding

Students whiteboarded yesterday’s problems, then we played the mistakes game. Students seemed pretty confident by the end of the hour, so hopefully tomorrow’s acids and bases quiz will go well.

IMG_1870

Day 152: Curved Mirrors & Neutralization 

/ Marta R. Stoeckel / Leave a comment

Physics: Curved Mirrors

We started by whiteboarding yesterday’s reflection problems. Along the way, I had a student stand in front of a nice, long horizontal mirror while someone else held a whiteboard between the student and the mirror to show a blocked object can still form an image. Afterward, students started making some qualitative observations about curved mirrors. My favorite part was when students noticed the hologram mirror I had out and start puzzling through what was going on. Even once the opened it up, students were eager to try changing the setup to see what would happen and test their ideas. I think some students were legitimately excited when I told them we’d draw the ray diagram for it later this week.


Chemistry: Neutralization Reactions

Students practiced determining the products in neutralization reaction. I was pretty pleased when a student asked “Aren’t these just double replacement reactions?” Last tri, a lot of students struggled to connect one day in class to the next, so this tri I’ve been much more intentional about trying to help students make those connections, so it’s gratifying to see students looking for links between new and old topics unprompted.

Day 151: Mirror Problems & Antacids

/ Marta R. Stoeckel / Leave a comment

Physics: Mirror Problems

Students worked on some planar reflection ray diagrams from the Modeling Instruction curriculum. They seemed to be getting some important ideas in place about the ray diagrams.

Chemistry: Antacids

Students had to design an experiment to determine which of several different antacids is the most effective. It was clear that my students had not had many opportunities to design their own experiments, so there was a little panic at first, but they were able to come up with a procedure with a little nudging. I used 3 M HCl and the pH didn’t budge much with any of the antacids, so we had some conversation about what it means to have an inconclusive experiment in science. The other chem teacher used 1 M HCl, and got some very noticeable changes in pH after using the antacids and was able to make a reasonable comparison.

IMG_1867

Not much change in pH

Day 150: Reflection & Acids & Bases

/ Marta R. Stoeckel / Leave a comment

Physics: Reflection

I put out some plane mirrors and reflectors, then tasked students with figuring out some rules for plane mirrors. In particular, I asked them to determine how the incident angle compared to the reflected angle, to compare and contrast the object to the image, and to determine where the image is located. The hardest question by far was where the image is located, since many students considered it “obvious” that the image is on the surface of the mirror since that’s where the light hits. The reflectors were especially effective for getting students to see the image is actually behind the mirror since the image could be covered and placing their pencil to trace the image provided a very tangible way of understanding where the image is.

IMG_1866

Chemistry: Acids & Bases

Students did a short reading on the properties of acids and bases. Looking back, I’d like to try revamping the pH lab I used last trimester, where students measured the pH of  various household chemicals. I think if I had students make more observations about the properties of the chemicals they tested, students should be able to build the same list of characteristics that shows up in the reading.

Day 149: Whiteboarding & Equilibrium

/ Marta R. Stoeckel / Leave a comment

Physics: Whiteboarding

I had all of my students for the first time this week! We did some abbreviated whiteboarding of the labs and problems from this week as a way to summarize the big ideas we’ve been working on.

IMG_1861

Chemistry: Equilibrium

Students set up a reversible reaction in several test tubes, then experimented with how to change the equilibrium. Afterward, we spent some time discussing the role energy plays in why some of the methods to disturb equilibrium worked.

IMG_1860