Topper,+Allison


 * An Invisible Fir**e- From the article, I learned how dangerous hydrofluoric acid is and the type of damage it causes within the body. From biology class, I knew how cell membranes were nonpolar because they are composed of a bilayer of phospholipids, so the uncharged, nonpolar end is on the surface of the cell. This makes it easy for the hydrofluoric acid to pass deep into the skin, because the molecule is uncharged. I learned that even though hydrofluoric acid wouldn’t be considered the most deadly acid, it can cause damage because of how electronegative fluoride ions are, which I remembered from honors chem. Because of this, I learned that the fluoride ion in the acid breaks free once it enters the skin and binds with calcium and magnesium ions and the hydrogen ion changes the blood pH; both of these things end up killing the cell, because I knew that the enzymes in the body have specific pH range. I was also surprised to learn how hydrofluoric acid causes very little physical damage when it is absorbed in the skin.

Allison, Good reflection on prior learning! Fluoride basically gets a better deal with Mg or Ca ions so it leaves H and binds with them. Well done! 5 stars. MW


 * Influences of Ancient Greek on Chemical Terminology**- I learned how much the ancient Greek language influenced the naming of elements and many other terms used in chemistry. I thought that it was interesting that most science terms come from the Greek and Latin since early scientists had to know these languages to be considered educated. I knew some of the common prefixes, especially the numbers, but I didn't realize how many elements were named from Greek words. I knew gold and silver were named after their Latin names, but didn't know that elements were sometimes named just by combining Greek words that described the element; like Bromine is named after the Greek word for stench, since it smells. Knowing what some of the root words are can be helpful when I come across some term I don't recognize so I can try to piece together a definition from the Greek roots.

Allison, I see your points of interest but did you follow the prompt and find 3 VIP's and an MVP? Not sure I can pick those out of your post. 4 stars. MW


 * Einstein’s Miraculous Year- ** The most important fact (MVP) I got out of this article was in the year 1905, Albert Einstein, contributed three important theories/ideas to the scientific community; the theory of relativity, the atomic theory, and the photoelectric effect. My first very important fact was that the photoelectric effect says that light behaves in a stream of particles and not in a wave when it interacts with matter which changed how scientists thought of electrons. My next MVP was that Einstein studied the motion of dust particles in water and made calculations that showed the dimensions of an atom. My third MVP was that Einstein figured out that time and space are all relative to some frame of reference. Einstein must have had plenty of time in 1905 to do all of this research!

Allison, I think he was working at a post office at that time. Apparently he liked to do "thought problems" so I think he worked a lot of this stuff out in his imagination. 5 stars. MW

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**Polymers in the Field and Track**- One thing that I learned from this article is the fact that the rubber pellets that provide cushioning (turf turds, as many Central students call them) are actually made from recycled automobile tires. I thought the temperature studies were very interesting since I personally have experienced how hot it can feel on turf. I knew it was hotter but I thought it was really interesting that a few centimeters above the surface it was almost 20 degrees cooler. One thing that I picked out of this article that relates to our class is the impact of the high specific heat of water, which we discussed during thermochemistry. Because water has such a high specific heat, spraying it on the turf cools the turf down and keeps it cooler longer. ====== Allison, Thanks for the laugh on the name of the rubber pellets! Good post 5 stars. MW **Salting Roads**- From this article, I learned the science behind keeping the roads ice-free in the winter. My first VIP was that highway workers put ice on roadways before it snows so as the first flakes fall, the ice dissolves in the snow that melts and forms a solution that won’t freeze. My second VIP was that highway workers put salt on roads that already have ice because the melting process begins when the salt and ice come in contact and the salt and ice crystals react forming a salt solution. My third MVP is that some road crews have experimented with using other salts like MgCl2 because it produces 3 ions when it dissociates which effects the freezing point depression. My MVP was that getting water molecules to form a crystal from a solution requires more energy so a solution freezes at a lower temperature than the lower freezing point, because this is why road workers use salt to prevent icy roads.

Allison, Once again a surgical strike by you! You really pulled out some great information from this article. 5 stars. MW


 * Pool Chemistry **
 * 1. How much more frequently does the pH of the pool have to be adjusted during the swimming season or other periods of high swimming activity? **

One thing that I learned from the tour of the pool is that the pool constantly has a source of sodium hypochlorite that is monitored by a computer that will increase the ppm as needed. Because of this, events that have a high volume of people in the pool will instantly have more chlorine to make up for the loss. The pH has to be tested at least twice a day, while Central tests the pH of the pool 3 times a day normally.


 * 2. Is it easier to adjust the pH of the alkalinity of the pool? Which of these has to be adjusted more often? **

Jason didn’t really talk about the alkalinity of the pool during the tour, so I am going to assume that the pH would be what is easier and more frequently adjusted. I know that the pool uses muriatic acid when the pH needs to be adjusted and the acid is poured around the edges of the water so it can disperse. With the chlorine regulation system, though, the pH doesn’t significantly fluctuate very often.


 * 3. How often does the pool have to be shock treated and how long after the treatment can swimming begin? **

The pool is not regularly shock treated with large amounts of chlorine (or sodium hypochlorite) unless a swimmer would throw up or have diarrhea because health department laws require that any time a blood born pathogen is entered into the pool, the pool must be shock treated. After a shock treatment, swimmers must wait 45 minutes to an hour before swimming.

Allison, Looks spot on! Well done. 10! MW


 * Flaking Away**- One thing that I knew before reading this article is that rust is a result of an oxidation and reduction reaction from our discussion in class. I also knew that an anode readily gives up electrons, or is oxidized and that cathodes accept electrons or are reduced. I also knew that the salt from salting the roads or the sea spray on the cost create more rust problems in those areas because of the water becomes a better conductor with the salt, increasing the ion flow in the solution. One thing that I learned from the article was that the chemical composition of steel gives it a surface that isn’t uniform, which creates regions where the iron can be easily oxidized. I also learned that researchers are trying to make paints that inhibit rust or ooze back together after they are scratched which would protect the iron or steel under the paint even more and save car owners the money of fixing the scratch right away to protect the car. I also learned that when zinc is used to galvanize iron or steel, it goes through a whole series of chemical reactions between the oxygen, water, and carbon dioxide to form the layer of zinc carbonate which protects the underlying zinc and therefore the iron from rusting.

Allison, Good mention of the zinc reactions! Well done! 5 stars. MW