We started by making simple models of atoms using paper plates. We looked at a periodic table to choose which atoms to illustrate, and made sure we had the correct numbers of protons, neutrons and electrons. We drew the protons with red pen and the neutrons with black pen on circles of paper, we used split pins to attach these circles to paper plates and drew electrons (with blue pen) around the edge of the paper plates so that we could turn the ‘electron shells’ as if the electrons were orbiting the nucleus.
We then talked a bit about quarks. I mentioned that quarks make up protons and neutrons. We talked about ‘up’ and ‘down’ quarks, and I told the children that quarks come in three flavours: red, green and blue. We glued sequins onto our atom models to represent the protons and neutrons being made up of quarks.
I made a joke about quarks being held together with gluons and the children gluing on their ‘quarks’.
A quick note here: the children in Science Club are aged between three and thirteen, I don’t really think that they will remember everything we talk about. But, I believe that if you use technical terms from a you g age then when you are trying to study them for real, the terms won’t be intimidating. I am a strong believer in a drip feed effect of learning.
We did a simple experiment next. I poured half a cup of water into a measuring jug. I asked the children what would happen if I added another half cup of water. They predicted that I would have one full cup measure of water. I did this and showed them they were correct.
I emptied my measuring jug and started again. This time I poured in half a cup of water and asked what would happen if I added half a cup of alcohol. The children hesitated, guessing there must be some kind of trick 😉
I added my half cup of alcohol and the resulting liquid was just below the full cup measure.
We talked about why this had happened. Then I fetched dry cup measures and used polystyrene balls to represent water molecules and sand to represent alcohol molecules. The sand filled in gaps between the polystyrene balls, not raising the level of the mixture at all.
Next, I gave out polystyrene balls and cocktail sticks. I showed the children a model of a water molecule made with my Molymod kit. They made their own models using polystyrene balls and cocktail sticks. We talked about how water expands when it freezes and tried to model this with our ‘water molecules’. (I had this picture in mind, though I think we established the general principal rather than making a very good model ourselves).
Our final experiment was a bit tricky. We tried to estimate the size of an oil molecule.
We measured one droplet of olive oil, then let it drop onto a big bowl of water. We watched the oil spread over the surface of the water, when it looked like it had reached its greatest size, we measured it.
We calculated the volume of our droplet of oil. Then we used that volume to calculate the height of our mini oil slick.
I suspect our measuring was a little inaccurate, but we calculated the height to be 0.00009mm, which isn’t completely crazy. You can see the experiment done more accurately here.