Forces
We started this unit with trying to see how many drops of water we could put on a penny. I was able to put 84 drops on my penny. The purpose of this demo was to introduce the idea of polarity.
We used this two different types of sands to see what happens when they interact with water. We saw that the green sand mixed with water, while the blue sand repelled water. No matter how much water you put on the blue sand, it always remained dry. We learned that the outside of the blue sand was non polar, with an umbrella of CH3 on the outside, repelling the polar water molecules.
The pepper soap water demo showed us how something non-polar, like soap, when placed in a polar substance, water, will move away from each other. The pepper was there to give us a visual on where the water was moving.
This was probably the most interesting lab in this unit. We wrote with dry erase markers on a plate, then poured water on it and watched the letters peel off and float in the water. After doing some research, our class believes that this had to do with polarity and how the pen pigment and water reacted with each other to create a force.
Our fourth journey this semester was about forces. Before we could truly understand forces, we had to learn about polarity and how to tell whether a molecule was polar or non-polar. We used lewis structures to determine this. When something is polar, it means that it has an unequal distribution of binding energy pulling from the center of the compound, making it have semi or full charges. With that we then learned how different polarities and ions interacted with each other. The different forces creates different states, such as gas, liquid, or solid. There were so many fun and interesting demos in this unit, which is probably why this has been my favorite units this semester. I think one of the hardest parts of this unit was trying to figure out how certain things worked in the demos, but this is also why it was so fun and interesting. We used the knowledge that we already had to try to solve the mystery of what was going on in the lab.