Courtney+Hastings

I thought that the second graphic was the most insightful. I found it the easiest to understand because it very simply classified matter. The second graphic was a web that had branches coming off of matter. Mixtures and pure substances came off of matter. Off of mixtures came heterogeneous and homogeneous, and off of pure substances came compounds and elements. This graphic was the easiest to understand because it was very simple, but still had all of the needed information. If I was doing an assignment, this is the graphic I would use. The only downside to using this graphic is that there are no examples included. This graphic was similar to the other graphics because they all classified matter using some sort of a web. They were also all fairly easy to understand. The second graphic is different that the first graphic because the first graphic has pictures, and the second does not. The second graphic is different than the third graphic because the third graphic included examples. In conclusion, the second graphic clearly classifies matter, while differing from the other two graphics.

Good Post! MW

I remember reading about chromatography in the textbook. However, I didn't know how simple it would be to do. I thought that the lab we did with M and Ms and Skittles was very interesting. It really showed me how chromatography can be used in the classroom. I thought it was a lot of fun. I think that distillation is an interesting way to separate different components. I really liked the example of taking salt water and using distillation to get fresh water. This method of separation is useful to countries without a fresh water source. Filtration is something that I am familiar with. An example of filtration is when I make macaroni and cheese. After boiling the water I dump the noodles in. Once they are soft, the water must be removed. To remove the water I use filtration. To separate the water from the noodles, I dump everything in a strainer. The strainer acts as a filter and allows the water to be removed through thProxy-Connection: keep-alive Cache-Control: max-age=0 20bottom. However the noodles do not fit throProxy-Connection: keep-alive Cache-Control: max-age=0 h the holes that the water did, so they are left in the strainer. This is a method of filtration that I am very familiar with.

Another interesting post! I love the mac and cheese example! MW

Measurement plays a huge role in my life. I really like to cook, and when I cook I have to make sure that I get the correct measurements. Wrong measurements means disgusting food. I would be very upset if I took the time to bake a cake, and then found out at the end that I had measured incorrectly. If that had happened the cake would taste bad and would be no good. I would be very upset if I had to throw away a cake just because I measured incorrectly. Another instance where measurement is important is in softball. In softball the bats we use are a certain length. Bat lengths are determined by the height of the owner. I use a 32in bat. My bat allows me to reach all of the plate, but not too much. It is just the right length. If somehow the company that makes the bats screwed up the measurements, all of the bats would be wrong. It would be impossible to try and use a bat that isn't your size, because you wouldn't know how big it is. For example, if I had a smaller bat than usual I would be thinking that I could reach farther with it than I actually could. Most likely I would strike out. If I had a bat that was too long, I would hit the ball, but not on the sweet spot. I wouldn't hit the ball on the sweet spot, because the sweet spot would be in a different place. I would most likely ground out. Therefore, in softball, it is very important that the bat you are using is a correct measurement. In conclusion, measurement affects a lot of what I do; two things being cooking and softball.

Courtney, Wow you have given this a lot of thought. I like to cook too so I can identify with your cake example. Great Job!! MW

When I read "Redefining the Kilogram" I learned some things that I had not known before. I did not know that the kilogram is one of the seven base units of the International System of Units. I was suprised to learn that the international prototype has lost mass over time. I would have thought that since it is the international prototype, that it would be the most accurate. However, I guess that this is not true. I wonder what it would be like to see the copy of the kilogram in Maryland. I think it would be an awesome experience, even though they probably don't allow students, or anyone near it. However, I am very glad that it is so well protected, seeing as there are only 90 copies in the entire world. Courtney, Another good post! It is cool to think that the prototype is very close to where we live. MW

I did not enjoy reading the article about airport security. It scares me to think that a bomb could be hidden in a doll, especially because I will be on an airplane this weekend. I am very glad that airports have all of the necessary measures in place to prevent bombs from making it all the way to the airplanes. I never realized how easily it is to plant a bomb. I thought it would be very difficult to get a bomb anywhere near an airport, but I don't think this anymore. I think that planting a bomb in a doll is a disgusting thing to do. Of all the places to plant a bomb, a doll? Really? However, I'm very glad that airport security is taking all of the necessary precautions to keeping everyone safe on the airplane. Before I read this article, I thoguht that airport security was extremely slow and I hated it. But now that I understand all that they have to do, I am actually glad that it moves so slowly. By airport security taking their time, they are reducing the risk of letting a bomb board the plane,%2

I think that the mole is a very interesting topic. I can't believe that someone discovered it in the 1800's. If I had discovered the mole, I wouldn't have known what to do with it. I wonder how chemists know when they discover something of value. I think it's sad that Avogadro didn't even know what he contributed to chemistry. He died two years before a use was found for his number. Luckily he was given credit even though he was not alive. Someone could have easily claimed that they discovered it, and then all of Avogadro's hard work would be gone. Chemists today are very lucky to have Avogadro's number because they can easily determine how many molecules are in an element. Without Avogadro's number this would be impossible. As chemistry students, we are lucky that Avogadro's number is so easy to understand, seeing as it is very important in chemistry.

I thought that the article about dust explosions was very interesting. I had no idea that sugar could actually be considered an explosive. It is terrible to think that people have died just because a cloud of dust caught fire. More should be done to prevent this from happening in the future. One step could be to clean up around the factories. If that dust had not been on the floor, it would not have caught fire. I think that dust explosions relate to stoichiometry because there has to be a certain amount of dust to react with the air. If there was less dust, there would be less chance of an explosion. Therefore, my solution of keeping the factories free of dust would help prevent the dust explosion problem.

Good points Courtney! MW

I thought the article on sulfur hexafluoride was very interesting. It's cool to know that different gases have such different properties. For example, helium makes your voice sound higher, and sulfur hexafluoride makes it sound deeper. I wonder who discovered that, and how they figured out that it would be okay to breathe in. I didn't know that when you breathe in helium you could actually die. But it makes sense, since you are breathing in helium instead of oxygen. When you deprieve your body of oxygen, of course bad things could happen. I also thought it was interesting that a sulfur hexafluoride balloon actually gets bigger over time. Instead of losing helium like a helium balloon, it takes in oxygen, which I didn't know balloons could do. I thought that they could only lose their gas; I didn't know that they could also take in another gas. This article was very interesting.

Courtney, Well written. A SF6 balloon would take in air not oxygen. I do wonder however if this idea could be used to separate the components of air? MW

After reading the article on motion detectors I understand what we are learning in class a little better. The article mentioned three ways motion detectors work. They can use echoes, light, or warmth. An example of echoes is dolphins. They use echolocation to find food when the water is too dark to see. The example of warmth will work for all humans and most mammals (I believe) since we are warm-blooded. The motion detector will pick up on the body heat we are emitting. The last way motion detectors work is with a light source. The way this works is usually with infrared radiation. The light beam shoots down from the source, and when something is in the way, the beam is blocked, which sends a message(?) back to the sensor. This lets the sensor know that something is there. After reading this article I feel every well informed on how motion detectors actually work, and why. Courtney, Looks good. Seems like you got a lot out of this article! MW