## Day 119 – Origin of Charges

Science 9 – Students used compasses and charging/discharging circuits to see where current flowed in a circuit.  This is a crucial lab to show that charges don’t originate in batteries.  Evidence for this is that charge flows on both sides of the capacitor and charges can’t get past the insulator in the capacitor.  As well, there is current when the circuit discharges without a battery.

This is such a great lab to do but it requires the right classroom culture.  Students have to want to find answers to the questions being asked of them.

## Day 113 – Pro D New Curriculum

Science 8 – Today there was a province wide professional development day for learning and collaborating about the new curriculum. The above graphic is from the science 8 curriculum. One thing I noted on this day was the importance of the kinetic molecular theory. I believe it will be a crucial unit for going through the curricular competencies. This is the unit where students will be using mass balances, graduated cylinders, collecting data, graphing, etc. I think that topics such as density, viscosity and pressure will all fit into this part of the curriculum. While I don’t think that learning viscosity has any large importance for students, it is clearly a good topic to investigate in order to learn and master certain process skills.

As an aside, a friend told me a story about the kinetic molecular theory. Apparently Richard Feynman was asked about what he thought would be the single most important idea or theory that should be passed along to a new civilization, if we could pass on only one. His answer was the kinetic molecular theory: that all things are made up of small particles which vibrate faster as they heat up. Or something like that. Anyways, it’s important.

## Day 103 – Viscosity Pt. 2

Science 8 – Following from last day, a few kids designed an experiment where they wondered what would happen to the pouring rate if the temperature was changed. That’s fantastic, because there is another lab in the textbook that covers this.

Today’s lab focus is data collection and graphing. They’ve already worked on experimental design and the procedure for this test isn’t very obvious. The graphing is a bit difficult though, because after the temperature of corn syrup reaches 55C, the data gets unreliable. They are measuring the time it takes for a steel BB to drop through 200 mL of heated corn syrup, and after 55 C the viscosity is so low that the time is less than 1 s. This makes timing very unreliable and inaccurate.

I looked over the Smarter Science sheets that the kids made and it was pretty good. The most difficult part of this process seems to be picking the dependent variable. What can the observe or measure that will determine if there is an effect or not? Many kids could not identify this, or also included independent variables.

## Day 100 – Viscosity Experiment

Science 8 – In science 8 we continue to use the Smarter Science framework for developing experimental design. For today’s class, I started out by pouring some corn syrup into a beaker of water. The idea was to stimulate kid’s observations and wonderment about viscosity. By having a beaker with water in it, the students are reminded that corn syrup and water are probably different.

I had the students fill out a level 2 Smarter Science experimental sheet, which I plan to take home and give feedback.

For today though, I took the idea that several kids had which was to test pouring rate. This is close to a lab that is in the science 8 textbook. So while the kids followed a set experimental procedure, I think many will have come up with the overall design of the experiment by themselves with correct dependent variable, independent variable, and control variables.

## Day 99 – Pressure and Math Cubes

Science 8 – Here is a photo from my other science 8 class. I used math cubes to model pressure. Each block represents one unit of force and the height of the blocks is units of pressure. Each block that touches the desk is a unit of area. We make a chart on the whiteboard with pressure, force and area and the students are asked to find patterns. Eventually we see that pressure x area equals force. Voila! we have P = F/A.  12 cubes works the best because factors.

I suppose you could call this “discovery learning” and I have no idea why you wouldn’t want children to experience it. They are challenged and engaged in the activity and feel pride at the end of it. Some educators say that we should simply tell them P=F/A, in order to reduce their cognitive load.  I guess this comes down to what you value in education.  For me, I simply cannot imagine what is so important about P=F/A such that a student really needs to know anything more than the idea that surface area spreads force out.  And frankly speaking, most of high school science is like this.  For me, the process is the important part.  Challenge their reasoning, their ability to make inferences, to recognize patterns and turn them into a model that can make a prediction.  That’s what I’m talking about.

## Day 97 – Really, Why Do Things Float?

Science 8 – In my other science 8 class we have finally got to the point of answering the question as to why things float. We know that density is a test/predictor as to whether an object will float but now that we’ve discussed forces we can say why something floats – buoyancy.