# Day 25

Physical Science: We started out the hour looking over the Graphing Applications assignment from Friday. The assignment, graph wise, was well done. They plotted the given data well, and added a line of best fit. Slopes and y-intercepts were found, and most kids had correct use of units with this.

Things begin falling apart when it comes to interpreting the slope and y-intercept. We don’t get into line equations, but rather qualitatively discussing what we can learn from the slope and y-intercept. Like I’ve said before, I try to get away from a math discussion as much as possible, and focus on what it learned from the experiment. We will be continuing working on defining the meaning of the slope and y-intercept.

After going over the assignment, we did a lab activity where students measured the diameter and circumference of a circle. This is the first activity that really brings together everything from the Science Skills unit. They have to:

– define background terminology

– take proper measurements in lab

– create a proper graph, find slope and y-intercept

– Craft a proper Claim-Evidence-Reasoning statement for a conclusion.

Tomorrow we’ll check it over, and discuss results.

Chemistry: We began by going over the exam from Unit 1, which was mostly a big positive. I would say 90% of the kids showed mastery on 7/10 Learning Objectives, which is pretty positive for the first unit.

We then began looking more in depth at matter. Unit 2 and 3 will focus on the differences between the states of matter. So to get us going, I did a demo where students had to discuss how we smell things. Then to kick off this “Smelly Demo” I poured some Peppermint Essential Oil on a watch glass at the front of the room, and students indicated when they were able to smell it.

I make the kids spit out gum, get drinks, etc. to ensure that their olfactory response is not compromised by outside factors. I also air out the room really well before hand. I also do not tell kids what the smell is going to be. I don’t want them to have a psychosomatic response, and think they smell something they don’t.

The kids then had to create a white board explanation as to how the oil particles got from the front of the room, to the back of the room. We’ll look at them on Tuesday.

Physics of Light: This was one of the best discussions my Physics classes had had in a long time. We just finished working out Snell’s Law, and I gave them an assignment to work on over the weekend. We ran into 2 big discussion points along the way.

The first was a question where light particles are trying to exit a medium, into one with a lower index of refraction, but we kept getting a calculator error. the kid presenting said, “I’m not sure why this is, but obviously something about the difference between substances is allowing it to leave the first medium. Why, I have no idea.”

Interesting.

The other question was about a light ray entering into a equilateral triangle, and exiting the other side. There was a lot of discussion about the geometry of the situation. Some people believed that the entry angle and the exit angle should be the same, because it “makes sense.”

Argument 1:

Others argued that it couldn’t be true because the angles are all different since the surfaces are not parallel to each other. We had our presenter do his thing, and then the debate began. I sat back for about 10 minutes and let it play out, and as time ticked away, more and more people were convinced that the angles couldn’t be the same.

Argument 2:

Except for one student. He was adamant that the first situation must be right. That was until they presented this question:

“Oh, I get it. Here they are similar because of the parallel boundaries, Alternate Interior angles. Never mind.”

Modeling works the best when students step up and have these discussions. At first it was little crazy, but as more and more people listened to the ongoing debate, they started to see the “bigger picture,” and focused on the physics. Sometimes these debates just turn ugly, and accomplish nothing at all. However, when you can create a classroom environment where open debate is okay, and respectful, you can accomplish a lot. Which my kids did yesterday.