Week 23

This week in Chem, we tackled a whole new part of chemistry.  Particles that are smaller than the atoms themselves.  So far, we've begun to tackle the electron.  To introduce the concept at first, we did a very simple lab in which Mr. Abud rubbed a pen on his shirt, and circled it around a match balanced on a cologne bottle.  This match followed the pen with no contact! We determined that the match moved thanks to the electrostatic charge. By rubbing the pen on his shirt, he charged it and changed something about the particles that we do not yet know.  We did a small lab with two pieces of tape that were ripped from each other and put them near other objects to see if they'd attract or repel, and came to the conclusion that opposite charges attract, and same charges repel.  With the fact that there are things smaller than atoms, we needed a new way to draw particle diagrams.  We now use circles with dots in them to signify the electrons.  So, to differentiate between the negatively charged and positively charged objects, we have more electrons in the one that's negatively charged.  This follows the theory that we are going off of for particles.  The theory we use says that there's a surplus and deficiency of 1 single type of particle.  The other theory we are aware of is that there may simply be 2 types of particles, positive and negative, but we have no proof for that yet.  We also learned of a new property called conductivity.  Conductivity so far, means that the electrons can flow through.  So we played a game.  This game was called Will it Conduct?  In this game we had a small circuit consisting of three wires, two batteries and a light bulb.  We had the batteries connected to the lightbulb through the wires, but also connected some substance in the circuit to see if the lightbulb would still light up.  We concluded that all the metals would conduct, and nonmetals did not conduct.  There's still so much to learn in this unit and I look forward to discovering the more in-depth concepts.

Week 22

Week 22 was a little less about chemistry. We only had 2 full days and 3 half days, leaving us with only 3 chemistry classes. This week's schedule was because of the standardized testing that the juniors had to do. So, sophomores took the ACT Plan. I thought that the plan was very easy and I was in good shape for next years ACT. The juniors had more tests, though, which left us with a few half days. On these days we had classes 1-3 on one, and 4-7 on the other. Our chemistry consisted of continuing our work with balancing equations. We focused on using the importance of ratios to be able to balance equations. Using ratios and phrases like "combines with" along with small pictures, balancing equations is a piece of cake. As class ended, we started with the concept of moles and mass while balancing equations and how we can find those in the process.

Week 21

This week in Chem, we continued our exploration of counting particles. In the beginning of the week, we continued our work from last week counting the number of particles in a certain amount of something. To count these particles we use moles. We practiced by using dimensional analysis to make sure our units came to cancel out and leave us with whatever we needed to find. So we came to possibly one of the coolest experiments we've done so far, in my opinion at least. We electrolyzed water, separating molecules into hydrogen and oxygen gases. To do this, we had a trough filled with a sodium hydroxide solution and two prongs sticking in the water. We placed test tubes filled with water on each prong, and connected two wires to the bottoms of the prongs under the trough. These wires were connected to a genecon that we consistently spun. The test tubes began to fill with hydrogen gas in one, and oxygen gas in the other! We went until we had 7.0mL of hydrogen gas and 3.5mL of oxygen gas. This proportion also proves that the water formula is H2O. There was double the amount of hydrogen gas as oxygen gas. We could then find the number of particles by again doing the dimensional analysis to find how many moles in each. We found that there were 1.6x10^-4 moles of oxygen, and 3.2x10^-4 moles of hydrogen. Another proof of the formula for water, H2O! It shows us how the empirical formula works out to be H2O with double hydrogen as oxygen. We finished the week off with an assessment covering everything we've done the past 2 weeks, and I feel very comfortable with it. I'm starting to like how we're learning more like the other classes have and am curious to see how the rest of the year plays out.

Week 20

During week 20, we mainly worked with the concept of moles. At the beginning of of the week, though, we did the experiment lighting the magnesium on fire again. This time we finished it though and ended up concluding that the magnesium had gained mass from lighting it on fire. This means that the product must've taken in particles from the air. Then, indirectly we began working with moles. We started in class with six containers containing six materials in each. We were asked to then find the relative mass of each by comparing them all to one of the items. Mr. Abud then introduced the mole to us. A mole answers the question of "how many" and is equal to 6 x 10^23 particles. Also, molar mass is the mass of a substance on the periodic table except measured in grams. You can find the amount of molecules or weights of moles with various substances, and can make it easier if you incorporate the phrase "for every" while working with your information. The week was a bit repetitive, but was necessary to get the idea into our heads.

Week 19

Week 19 was an odd week for the Chem team. On Monday, we tried an experiment in which we mixed hydrogen chloride with a pebble of zinc to produce a gas. However, the experiment didn't produce any gas. So, the next day we tried the same experiment using a more potent hydrogen chloride. The two reactants were placed into a flask that was plugged with a stopper that connected it to a trough. We then had a bell jar in the trough filled with water. As the gas was produced, water left the bell jar until there was only gas left. We carefully removed the jar, trying to let the least amount of gas escape using a watch glass under it. To test if it was combustible, we lit a match and held it under the jar. Quickly removing the watch glass, the gas escaped and combusted down onto the table and made a popping noise. We found out that the gas produced here was hydrogen glass. We then moved to practicing balancing equations which is still very difficult for me. I will need more practice with it. While working with this concept we learned a few things. First, we know that the total number of particles in a closed system gets conserved which helps us balance equations. Then, we learned all the diatomic elements using an acronym. Dr. Hofbrincl, standing for: hydrogen, oxygen, fluorine, bromine, iodine, nitrogen, and chlorine. Finishing the week, Mr. Abud did an experiment for us lighting a piece of magnesium on fire. It was a very cool experiment, watching the magnesium ignite and get so bright so quickly. However, we didn't get to finish it and mass the magnesium afterwards. We would have had an assessment at the end of the week but had the pleasant surprise of a snow day!

Week 18

Week 18 continued with more in-depth learning of Unit 4 and studying properties of atoms, molecules, and elements. Starting off the week, we did an activity in the computer lab in which we went back to Dalton's experiments with phlogiston and oxygen, and discovering the fixed ratios of elements. We came to a few conclusions in class using what we did: 2 substances with the same properties have the same ratio, the mass of a solid lost is equal to the mass of a gas produced when heating, and there are fixed ratios within systems. We moved to more about diatomic elements and how we can tell they're diatomic. Like with hydrogen chloride. If 1 vol. of hydrogen is combined with 1 vol. of chloride, but 2 volumes are produced, then you know they're diatomic elements. Then we came to some conclusions. First, we know that substances and compounds are composed of individual particles. Substances are made out of elements or pure substances. Compounds, however, are made of multiple particles that are either the same or different. Lastly, we concluded that particles combine to form molecules. To end the week, we came to our final conclusion that diatomic elements stay diatomic until they have something to combine with. We had an assessment on Friday that I feel good about, and look forward to seeing my results.

Week 17

In the beginning of the week, we had a few educators from around the state come in and watch our class. They took videos and pictures of us and how we use technology in the classroom. The day that they were there, we were trying to figure out the percentage of water in a can of Pepsi. So we basically took a 100mL sample and distilled it. Unfortunately though, we didn't wait long enough for all the water to come out of it and when massing the Pepsi, we made some errors so it ruined the result. We couldn't accurately measure amount of water that came out. That day, we also learned what a colloid was. A colloid is a mixture in between a suspension and a solution. One that will not unmix by itself but is partially dissolved. We continued discussion about mixtures and compounds and the differences between the two. This took us to the concept of fixed ratios. The ratios of atoms in a mixture do not matter, while they do in a compound. If the ratios weren't the same in compounds then it wouldn't be the same molecule. From there, we moved to nomenclature. Nomenclature is the naming system for chemical compounds. There are a few rules we have to stick by like when there's only one atom of the first element, there's no need to say "mono" before. Rules such as this allow us to name compounds that we don't already know the name of. Also, there are two main classes of elements: metals and nonmetals. When naming two nonmetals, you need a prefix but with metals and nonmetals, you don't. Then we learned that there are some elements that are diatomic, which means they come in pairs. We finished the week learning that volume of a gas and number of particles is proportional. We have midterms coming up, and I'm extremely nervous for them. We'll see how it goes.