SG chem 2a

This week in SG chem was very exciting!! We started off monday and tuesday reviewing for our unit 4 test. We had a review guide and we pretty much just went over the stuff we've been working on for the past couple of weeks. We went over the differences between elements, compounds, mixtures, and pure substances (For example, we know that a compound can be separated by electrolysis, a mixture can consist of two or more elements in a fixed mass ratio, and more!!) After that we went over how to sketch particle diagrams.

 

All of this was fairly easy except at first I didn't really understand why diatomic meant. I knew that if they gases were diatomic, the volumes of the gaseous product would double, but I wasn't 100% what it really meant. However, I know that the "di" in diatomic means 2, so there's 2 atoms instead of 1 in normal gases.  The last things we reviewed were different mass composition problems and sketching graphs. 

 

Again, both of these things were straightforward and since we spent so much time white-boarding and learning the material, it was a breeze! We took our test and I honestly thought it went really well, but turns out I ended up getting a 31/34, so I need to go back and check what happened with that. 

The very next day we started unit 5 (which is about counting particles) and we immediately got the unit objectives. The first one was about Avogadro's hypothesis, but that was review from last chapter The second object, however, was a little different. It says, "Use experimental data to determine relative mass of two objects." At first, I was really lost. I remember learning a little about it in chem 1 (but I took that class as a freshman, so it was kind of long ago), but then we did a worksheet and it started to make a little more sense. 

We learnt unit conversions, and one main thing I got out of this worksheet (along with many other things) was that in order to find the average weight, all you have to do is weigh the box, then the stuff inside the box, then weight them together, take the difference and then just divide by the average! So easy! I would have never thought of that until we did this activity. The back of the worksheet (more specifically, the last problem- the extension) was the most interesting to me. It was really cool how we connected everything we had just learnt with the stuff we learnt in the last unit. It was also cool, because this was how the scientists way back then did things and it was awesome to see something from their perspective and actually figure out the reasoning to what they thought back then. 

The last thing we did this week was a worksheet. It was about molar masses of the elements. This worksheet was pretty similar (lots of math so that sucked!!), but we didn't have a chance to finish it in class, so I'm sure we will go over it in greater detail tomorrow in class. The last couple questions are all reflection questions, so I don't think it'll be too difficult. 

Can't wait for this new week! Love science! :)