Week Seven

This week, we started by looking at the ethanol and colored water a little more. Now, though, we were focused on the concept of expansion, which is the process by which the volume of a substance increases, but mass stays the same. Also, expansion can occur without a state change, but it does require energy, as does a substance when its state changes. The change in height is a way to measure the expansion, but you can also measure the motion of particles by using the temperature. It measure the energy and the motion of particles. Then, we began our work with pressure. Pressure is measured in Pascals, and can be measure by taking force divided by area. Pressure is a push or a pull that is applied over a certain area. The more area there is, the less force that is applied at each point of pressure. We discovered this by doing an experiment in which a balloon was pressed onto a bed of needles, and it didn't pop. Then, the balloon was pressed onto a single needle, and it popped immediately. With this talk of pressure, we learned how we are able to drink through straws. We drink through straws by exerting a pulling force on the air in the straw. This makes it leave the system, which leaves no force pushing down on the liquid. Without this force pushing down, the liquid is able to rush up through the straw, therefore, you drinking it. To end the week, we were divided into several groups to do experiments each dealing with pressure. My group did one that compared pressure and temperature. We had a test tube that was closed and connected to a pressure meter. We placed the test tube in a beaker full of water, and instead of adding heat to the system, we used ice cubes to make the water colder. At five 40 second intervals, we added two ice cubes to the water and recorded the reading on the pressure meter. Our results showed that as temperature decreased, pressure did as well. This means that if temperature were to increase, then the pressure would increase with it. The past week in Chemistry was just again showing that learning is easy, and making it fun helps more than simply doing traditional homework.

Week Six

In the past week, we have done no labs, just class experiments that Mr. Abud has lead. We have just been taking notes and learning new concepts. In the beginning of the week, we started with a block of dry ice that Mr. Abud moved around. The vapor coming off of it showed the particles that were leaving the system. This showed a solid going straight to a gas form, which can be described as sublimation. Then, Mr. Abud cooked a bag of popcorn, that we sat and waited for the smell of it to reach our seats. That day we learned that particles are always in motion, whether matter is in a solid, liquid, or gas state. With solids, particles are always in motion. In liquids, particles are always in motion, but heat makes them move more quickly and coolness makes them slow down. When we talk about particles moving, they can move translationally, rotationally, and vibrationally. Also, the particles can slide past each other, which brought us to the concept of fluidity. Fluidity is the physical property that enables something to flow. Liquids and gases have fluidity while solids do not. The opposite of fluidity is viscosity, which is the resistance to flow. The three states of matter, obviously, have different densities. Solids are the most dense, then liquids, and lastly gases. These densities may have a role in the fluidity/viscosity of each. We also learned a term-Brownian motion-that describes how particles move in all different directions. To finish the week, Mr. Abud lead an experiment in which he placed two test tubes filled with water or ethanol in a beaker of water on a hot plate. As the water heated the tubes, we saw how the ethanol rose above the stopper into an additional type of tube. The ethanol rose higher and faster than the water, meaning that the ethanol had more particles that were moving faster and had more fluidity then the water. Lastly, we came to the conclusion/consensus that all energy is just simply energy. It is only stored and transferred differently.

Fifth Week

It's been so easy to learn more in chemistry the past week since it has been so fun. I stay active, and am able to easily pay attention instead of drifting off and daydreaming all hour. We continued working with density and applying what we've learned to different scenarios. In the beginning of the week, we planned a lab in which we would find the density of two students. We decided to use a 44 gallon trash can to fill water with, and then use the water displacement technique to be able find the volume of the student once they got in the can! However, the displaced water would not stay in the can, of course, so we put the can in the middle of a plastic baby pool. This pool would capture all of the water that flows out of the trash can. After the water was displaced, we would gather the water from the pool into 2 liter bottles, using small cups to scoop up the water and put in the bottle. By doing this, we could find the volume of each student. However, with one of our students the water rushed out too quickly and much was lost onto the lab floor, so we did not gather all of the water that was displaced and therefore got a lessened reading of the student's volume. The students that were used also weighed themselves the night before the lab, so that we could then convert their weighting pounds to grams. Also, we could convert their volume from liters to milliliters, and then find their density in mL/g. We found that our male student was denser than out female one, but he also weighed almost 60 pounds more. As the lab was going on, we had people taking videos, pictures, and working on a presentation of the data in a PowerPoint. It successfully displayed our data and results with plenty of pictures and videos. The next day we finished the PowerPoint on google drive, so that everyone could make edits and input data which was a very convenient thing to have. Friday we took our Unit 1 Assessment. I feel confident in it since I knew the standards well and felt very prepared. Like I said, learning is a lot more easy when it's fun and keeps you involved in an active discussion.

Fourth Week

The past week, we've mainly been working with density in the multiple experiments that we have done. First we did a candy lab, in which we tried to find the density off a non-normally shaped object. We worked with peanut M&M's. Although we could mass them, we were not able to simply measure they dimensions and find the volume. So, we had to use a new technique called water displacement. My putting water in a graduated cylinder and measuring it, we could drop in the M&Ms and measure the difference in water volumes to find the volume of the M&M. We could then divide the mass by the volume to get the density. Second, we did a lab to find the volume of a sheet of aluminum foil. We were given the density, and we could mass it. So, we had to be able to manipulate the formula for density and come up with the volume for the sheet. By finding out the volume, we found the height, which was the variable that we had to find. We ended our week of experiments with a gas lab. First we massed a flask of water and an alkaseltzer tablet. Then, filling a trough-like object with water, we could fill up a 295mL bell jar with water. Then, we put the tablet into the flask and covered it with a stopper. The stopper, though, had a tube coming out of it that led into the trough. The gas formed cause water to leave the bell jar and we could measure how much water was left in the jar at the end. With this we could determine the volume of the gas. Then, we massed the flask and were able to find the mass of the gas by subtracting the original mass from it. We did this lab in order to problem solve and find the relationship between the densities of gases, solids, and liquids. It was a very productive week and I was able to take a lot from it.