Sg Chem 2A!!!

This week in chem was particularly hard for me. We learnt lots of new material in a short amount of time. 

Sg chem 2a

We didn't do much this week in chem. We started off by learning about Polyatomic Ions. Polyatomic atoms are groups of atoms that carry a charge (and are found regularly in food, natural waterways, etc). In the worksheet we did, we had to identify and place certain elements into different tables. At first I was really confused. I didn't even really understand what an Ion was, but after we white boarded and discussed it as a class, things started to make sense. After that, we did Unit 6 Worksheet 1. In this worksheet we learnt about positively charged ions (cations) and negatively charged ions (anions) and we had to the write the formula and draw the particle diagram for each compound. This was pretty straightforward and as a table we were able to fly right through it! However, there was one difficult part. It was on the second page and you had to write each formula (from the previous page) in the boxes corresponding to its elements. This was really weird and hard for a lot of us to understand, but after Dr. J went over it as a class, it started to clear up. From this table we were then able to predict the formulas of the compounds formed by the ions below (for example: __potassium
___oxygen etc). After we got the basics down we started doing a bunch more worksheets. There was one (worksheet 3, if we are being specific) where we had to give the name of the following binary ionic compounds, write the formula for the binary compounds, write the formula for ionic substances, write the name using roman numerals, and more. Each table was assigned specific questions and then we white-boarded them and went over all of them as a class. The material itself is not too difficult, but going over them as a class definitely helped. It was also comforting that a lot of people were making the same mistakes as you. The next worksheet we did was about representing ions and formula units. The front side was extremely easy and straightforward, but the back was a little more complicated. On the back we had to also state the number of atoms and the number of ions in the compound, and honestly, I'm not completely sure how to do that. We worked on it as a table, but I wish we could've done it as a class. After this worksheet, we started to review for our upcoming test. We got a blue sheet with all the symbols and charges for Polyatomic Ions and that was a LIFE SAVER!!! That made pretty much everything really simple, because then we didn't have to try and memorize everything. For the unit 6 review, we were all assigned a problem and then we white-boarded like before. There were a couple things we skipped, but we basically went over everything. I think the hardest questions that I didn't understand were the last couple (for example: why do chemists refer to CO2 as carbon dioxide, yet use the name tin(IV) oxide to describe SnO2?), but at the end it told us exactly what to study and I think that was nice. It reminded us to be familiar with the names, formulas and charge of the common ions, know which combinations of elements give rise to ionic compounds and more. We also were given some extra practice that helped a lot too. Overall, I think this was a good week and I cannot wait to keep learning!! :)))

We did a lot in chem this week.

SG chem 2a

We had a pretty intense week in SG chem 2. We learnt a lot of new material and we are now getting ready for our next unit test (which will be on Friday, October 16th). We started of the week by doing a work sheet about relative mass and the mole. This is when we first even started talking about moles, and I didn't really understand what it meant. The worksheet was spilt up into three models and we worked in our table groups and after model one things got a little easier. Most answers were pretty easy and math was always simple, but you had to make sure you didn't over think some of the concepts.  We white boarded the last part of model three and once we figured out that everyone had the right answer we moved on. I'm glad we started with this packet, because it helped us flow into the next one.

The next worksheet went more in depth about moles and what they are. We learnt that one mole equals 6.02 x 10^23 and since it was hard to imagine that number, there were different analogies on the page to help us visualize it better. For example, it said that one mole of rice grains is more grain than the number of all grain grown since the beginning of time! Another one said that one mole of marshmallows (standard 1in^3 size) would cover the United States to a depth of 650 miles. That is INSANE! But also, SO cool to think about. Anyways, there were 3 problems on the bottom for us to do and we worked together as a class learning about unit conversions and the right way to do them. I think if you follow the method you showed us in class, they really aren't bad at all. 

The next thing we started was a lab. It was called the Empirical Formula Lab and we started off by taking the mass of the labeled beaker, then the mass of the beaker + zinc, and then we heated it up and took the mass of the beaker + zinc chloride and we kept doing that. 

Then we took some observations and then worked on the problems on the back which, thanks to the earlier worksheets, were pretty simple. 

 The last thing we did was white board all our answers on the front board and we came to the conclusion that the Empirical Formula that we all got was ZnCl2.

(here's a cute selfie of table 6 all being safe and working hard!)

The last thing we worked on this week (and got homework on) was a mole practice sheet. It's just a bunch of different and random mole problems, and personally, I think they're pretty easy. We did the first couple together as a class, and like I said earlier, if you do it the way you showed us, it's not that bad. However, we have a quiz on Monday, so this worksheet was good practice. 

We did these together

And this one we did as a table.

Anyways, that was pretty much all we did this week and we did get some more practice for homework this weekend, but I think it'll be good for us and help us prepare for the quiz. Can't wait for next week!! :) 

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! :) 

SG chem 2

This week was pretty busy. We learnt that we had a test coming up and we spent the whole week really understanding the material we were given and even learned some new material. We started off the week doing worksheet 3. In this worksheet we learned how to suggest formulas for the compounds by looking at the mass. At first, I didn't understand this at all. It didn't make sense that you could make a formula just from looking at compound b divided by compound a. However, after we did 3 or 4 of these kinds of problems, everything started to come together and I started to get how sketching particle diagrams and really thinking about it made sense. It's also important to make the compound numbers into improper fractions, otherwise it's really hard to see how many atoms of each element you're working with. We white-boarded everything as a class and even though the last question was really hard, it made sense when Toby came up and explained it in a different way.

Actually before that, we did some readings. We read all about Gay-Lussac and Humphry Davy and "The Race for Iodine". We did a worksheet on it as well, and I thought the reading was really interesting. Iodine is such a normal, common thing to hear about, but I've never really thought about how it actually came about. It was interesting how different Gay-Lussac and Davy were and how they didn't love each other because their countries were at war, but they were still able to discover iodine (not together, but both played major roles. Sucks that Davy was one day late!!). It also boggles my mind how these scientists worked without the technology we have today. Like the fact that Gay-Lussac flew 23000 ft in the air (by balloon!) to measure the earths magnetic field? That is insane. I'm not even completely sure how they created all the different elements (like sodium, potassium, magnesium, and more) in the first place! So crazy. 

We did a Daltons playhouse thing online (I was absent, but did it at home) and the last thing we worked on before the week was done was worksheet 4. Worksheet 4, in my opinion, was extremely easy. However, I think it was only easy because of how well I understood the previous material. I'm extremely glad we did the really hard stuff first, because now everything seems like a breeze :) Anyways, worksheet 4 was about expressing the ratios of the mass of each element to find the total mass and then figuring out, by calculating it mathematically, the percent composition of each compound. We only did the first couple problems in class and we white-boarded it afterwards and it seemed like every person in class got the same answer as my table. 

This is our board, shout out to Jimmy for his great handwriting!!

This was Maya, Nathan, and Philip's board, but we really liked how it looked :)

Anyways, that's pretty much what we focused on this week. I hate all the math we're starting to do (hopefully it doesn't get worse!), but as of right now it's not too bad and I'm feeling fairly confident about the test on tuesday. I think I just need to do a couple more practice problems like those in worksheet 3 and I will be all set!! Can't wait for a new week:)

SG chem 2A

 This week in SG chem we focused on lots of different things. We started off reviewing things from chem 1 and we whiteboarded different experiments we remember doing. Some of experiments include the popcorn experiment, the mass and volume experiment, and more. We also reviewed different kinds of graphs and particle diagrams and different terms and ideas we remembered (like the conservation of mass, for example). Next, we started talking about matter and how atoms combine to make different kinds of atoms. We did a worksheet and learned all about atoms and elements (and how an atom is part of an element) and molecules and compounds (and how a compound is made up of multiple molecules). We learnt how to tell if something was a compound, a pure element, or mixture just from looking at a picture.

 After that, we did another worksheet and practiced identifying compounds, mixtures, and elements.
We talked about salt and water and how things dissolve and how we can separate the liquids in different ways.

We also watched a video about how sugar reacts in different types of liquids (water, alcohol, and then a mixture of water and alcohol) and it was really interesting to see how fast the sugar dissolved in water, but how nothing at all happened when it was in the alcohol.  Finally, the last thing we did over the week was learn about Avogadro's hypothesis and we started a worksheet about it, but didn't get a chance to finish.

It was a really fun week and I look forward to learning more and doing more experiments!! :)