Here at Bloke School, we spend a large proportion of our time studying science in one form or another. It was kind of ironic that our initial approach to this field of reasoning and deduction was fairly haphazard.
We were following the curiosity of the day, having fun with it, and certainly learning a lot. Without wanting to detract from that, I wanted to add a structured undercurrent to what we were doing, especially after I met the assessor and needed to show some well defined justification for my decisions.
After a surprisingly lengthy search, I finally settled on the book Building Foundations of Scientific Understanding. This gives a years worth of weekly lessons. They build incrementally one onto the next in a nice orderly way. It still leaves us plenty of time to pursue our individual interests. What especially appeals to me about this book is that it applies the theme of easy complexity I keep referring to, although this time in a scientific rather than mathematical context. The lessons are very instructive, while being playful at the same time. It also provides us with a constant theme we can keep referring back to, rather than simply snatching out of a grab bag of interesting facts. Lately, we have been looking at the states of matter. Today we were looking specifically at how all matter is made up of particles.
Using the fairly universal glass of soapy water with a straw, we blew lots of bubbles to try and visualise gas as packages of particles. By popping the bubbles, we recombined our gas packages.
To try and demonstrate the idea of particles of water, we filled up a spray bottle, and sprayed mists of water. Also, by spraying repeatedly onto the same place, all the droplets made a little pool. In this way, we ‘put the water particles together again.’
To explain the particulate nature of solids, the boys took to a chunk of concrete with a hammer. They are old hands at this. We were able to visualise putting them back together again by looking at sandstone, and seeing how it is all the little pieces of dust ‘squashed into a rock.’
The boys spent a fair amount of time blowing bubbles, spraying water, and smashing rocks. Once they had largely had enough of that, I tried to move on to density. I really wanted to get across the idea that the state of matter comes down to how much ‘stuff’ is in a given space. (Yes, I know. Temperature plays a part too, but we did temperature last week, and I didn’t want to over complicate matters. You have to remember this is a kindergarten/ first year class.)
We talked about how you can feel wind because of all the particles bumping against your skin. Then we get on to how water is harder to push through than air, because the particles are closer together. If you try to move through a solid, you will just hurt yourself. There was no need to demonstrate this. They know it already.
In an effort to demonstrate the movement of gas molecules, we took small handfuls of flour, and blew them into clouds. We watched the flour dust blow around, and stuck our hands into the cloud to show there was plenty of space there.
The liquid equivalent of this was dropping a small pinch of flour into a cup of hot water. Again, imagining each piece of flour dust as a water molecule, we watched them being pushed around by Brownian motion.
I couldn’t work out how to demonstrate molecular movement inside a solid. They just had to take my word for it.
We had covered a lot of ground, and I was surprised to find we had only been going for a bit less than an hour. When the boys decided the best thing they could do with the left over flour was to tip it into the soapy water, we were able to briefly touch on suspensions. This is a familiar concept to them.
It was fun for them to them to work out that by blowing bubbles into the goopy suspension they had made, it was possible to have all three states inside a given space (the glass) at the same time. This seemed a good place to stop.