SG Chem 2 - Second Blog 9/25/15

For me the material we were started learning during this week in Chem 2a was a lot harder to understand than last week. We started going over brand new information about things like compound formulas and ratios (Unit 4 - Worksheet 3). I was not able to/still am unable to understand how to come up with the right answers to most of the examples on the sheet and am slightly overwhelmed about having to do it on the upcoming test. I think my main confusion is that I don't understand what all the numbers we're given (the mass of each element) and the numbers we find (the masses over each other) represent and how to use them to solve the question. I also don't understand what it means the difference between "Atoms of C and O have the same mass" and "Atoms of O are heavier than C atoms by the ratio compound in A."

Another thing that we did was we learned about different scientist from the past, including Empedocles, Democritus, Joseph Priestley, Antoine Lavoisier, John Dalton, and a couple more. We were first introduced to Priestley and Lavoisier through a video we watched in class. It compared the work of Priestly to Lavoisier and described how both were key components in discovering elements and that the thing scientists used to describe the chemical reaction in a substance, phlogiston, was not an accurate description of the change. I found this video very interesting and liked the fact that even though the two scientists had very different approaches to finding an answer, they both needed each other in order to make this new discovery.

To learn about the other scientists we got a sheet called "Matter." The sheet titled "Matter" explained the evolution of what scientist defined as matter.

Empedocles believed matter was made up of four main elements, water, fire, earth, and air, yet there were many flaws in this explanation of matter. Democritus helped shore up some of the flaws by creating a new theory. His theory was that everything was created out of pieces of matter so small that they could no longer be cut in half, he called this things atomos. He also believed that each material or substance had its own, specific type of atomos, and that two different things would not have the same type of atomos. I was really impressed at how people were able to make theories and discover these things with so little technology, just by what they were witnessing happening around them.

In class we started a experiment with a tool that would eventually separate two substances apart. We watched on logger pro as the graph started to resemble that of the heating curve of water. We were unable to finish the experiment in class but I found it interesting that you could separate the two substances because they had different boiling points. I'm not sure if I fully understood what the experiment taught us, but I think after discussing it some more with the class the main point will become clear.

I think over all this week was a lot harder for me to understand the material we were learning in class.  I realize I need to find a way to get an understanding of the lesson otherwise I will be more confused further down the road. 

SG Chem 2 - First Blog 9/18/15

     This week we learned about the difference between atoms, particles, and molecules, along with the difference between pure substances, elements, mixtures, and compounds. To do this we did worked in table groups on a sheet called the "Classification of Matter." The front page showed nine boxes with different shapes inside them. Each individual shape represented an atom, then atoms were combined together (by a chemical bond) to form a molecule. The amount of molecules in the area represented the number of particles in each box. After identifying each of these things we figured out which boxes were pure substances vs. which were mixtures and which boxes were elements vs. compounds.    
     Last year in Chem one,  my class was able to get to unit four, because of this I vaguely remember completing this sheet but I realized I had forgotten a lot of the information in this lesson. I found it helpful to go over the information again and the picture examples (the boxes on the front) really helped me get a better understanding of what each part was and how they connected to each other.
     One thing I find difficult to remember is the which type of atoms are compounds and which are mixtures. I can't remember if it's compounds are the ones that use "&" or if they are the ones that are "squished" together (vice versa with the mixtures). Another thing that I still struggle with is taking the information we learned about the difference between mixtures, compounds, elements, and pure substances and applying them to example pictures, such as what we did on the back of Unit 4 Worksheet 1. I was able to identify everything in the first row of boxes, but once I got to the second row, when the atoms starting forming shapes and condensing together, I got a little confused on which category each box would go into. I think with a little more practice I will be able correctly identify each category.
    An interesting experiment that we did in class was we took a sugar cube and put it in water, then we took another sugar cube and placed it in ethanol, then we took the last sugar cube and put it in a mixture of ethanol and water. We observed what happened to the sugar cubes in each liquid. In the water the sugar cube started to dissolve, in the ethanol the sugar cube sustained its form, and in the mixture some of the cube dissolved while most of it stayed intact. We learned even after a year the sugar would still stay in that form. 

Before

After

      I believe I participated a decent amount in the class, mostly in the table discussions. I try to help my table members when they need help and I contribute when I can. Sometimes when I don't understand a concept or am unsure of an answer I don't add my ideas to the conversation as much because I'm not sure what to say.