Mohn,+Austin

The attraction and charging of atoms are topics frequently addressed in the article "An Invisible Fire". Fortunately, I learned that a charged atom, or ion, is one that has gained or lost one or more electrons. I was also aware that high temperature burns are caused by extreme heat and that chemical burns are the result of a chemical reaction. This article informed me of the importance of calcium and magnesium in control of nerves and cell membranes. I didn't know that uncharged molecules could easily make their way into cell membranes and from there bind to enzymes that neutralize acids and keep the pH in our blood and tissue stable.

Austin, OK. Looks good! 5 stars. MW

I thought this article about the influences of ancient greek on chemistry was very interesting. My first two "very important points" were the charts on the first page listing Greek-derived prefixes and suffixes. Understanding prefixes and suffixes are key in order to break down the meaning of any word in any language. A few prefixes that jumped out at me were "hyper" and "hypo", observed in hyperchlorate and hypochlorite, "pyro", fire, and "thermo", heat. My last "very important point" was the chart on the second page listing chemical elements and their etymological meanings. It was interesting reading how much the Greeks were able to uncover about these elements that they reflect through the chemicals' names. The MVP that I selected was simply the conclusion paragraph because I feel it truely summarizes all of the main points of the article. "This artical has shown not only that many Greek-derived terms are used in chemisrty, but also that an elementary knowledge of Greek prefixes and suffixes, together with a few selected Greek words, can lead to a better understanding of the exact meaning of these terms."

Austin, There is no hyperchlorate. We call it perchlorate from per- meaning the maximum - in this case the maximum number of oxygens. Good post overall. 5 stars. MW

My first "very important point" for the article about Einstein was towards the end of the photoelectric effect section. The passage reads: "Higher-intensity light causes more electrons to be ejected, and lower-intensity light means fewer electrons as long as you are above that threshold frequency". I liked this quote because it easily explained and summarized the entire section. My second VIP was the last paragraph of the Atomic Theory section. I chose this because it explained the process that the atomic theory went through to become accepted. My last VIP was Einstein's reasoning that time is relative to your frame of reference. My MVP was the fact that Einstein discovered all of these things in the same year.

Austin, OK. The time relativity thing is somewhat difficult to grasp. 5 stars. MW

Polymers in The Field I thought that the naming for AstroTurf was very interesting. I didn't know that it was first installed in the Texas Astrodome because it was impossible to grow grass on the field. I also wasn't aware that so much thought went into the installation of the AstroTurf. The drainage holes placed every ten centimeters and the 0.5 percent slope from the center of the filed to its edges are only two of the ways the field is designed to efficiently drain water. I found it interesting as well that the turf has a density of 9,450 grass tuffs per square meter and that those annoying black granules that always get stuck in your shoes are actually shredded bits of tires. I really liked how this article incorporated science into a subject teenagers would understand. Austin, Drainage is interesting but did you find any relevance to chem class? MW

Salting Roads My first "Very Important Point" was the explanation of how/why liquids freeze. This was in the first paragraph of the Freezing Point Depression section. The passage explains that when heat is removed from a substance, the molecules slow down; ending with their freezing when they come to an also complete stop. This concept is vital in understanding why salt is used on roads. My second VIP's were the reasons why highway workers use salt on roads: to melt ice that is already on the road and prevent ice prevent ice from forming on them. My last VIP explained that magnesium chloride and calcium chloride worked better at lower freezing temperature because they broke into three ions as opposed to sodium chloride's two. The MVP I selected for this article was in the Salting Roads section because it explained that the addition of salt on roads lowered the freezing point of the water. This prolongs the build-up of snow and keeps roads safer for drivers.

Austin, I don't think you mean "prolongs the build- up of snow", as your MVP!?? That would cause greater problems! 4 stars. MW

Pool Questions 1. How does urine affect the water in Central's pool? As Mr. Jason Miller said himself, it's natural for swimmers to pee in the pool and is "no big deal". Urine is usually an acid falling around a six on the pH scale, but can sometimes be basic depending on the individual. Overall, urine may lower the pool's pH level, but other than that has minimal effect.

2. How do you monitor the pH level of the natatorium? The pH and chlorine levels are monitored by a computer system that automatically adjusts either to remain at a set value. The pool staff also checks these values manually three times a day through a process similar to that of pH paper; the water changes color when a chemical is added to it and the color is matched to a pH value.

3. How do chemicals on human skin affect the pH level? The various chemicals the body releases are most likely to lower the pH of the pool because they are mainly acidic. Sweat is one of the largest contributors of this concpet. The body also absorbs some of the chlorine in the water, also lowering the parts per million of chloride in the pool.

Austin, Great job! I can see you learned a lot from Jason and the reading! 10! MW

Flaking Away After reading this article, I was informed of the high expense of rusting on the United States. The article stated that "corrosion costs the United States... about $276 billion in lost goods and services." This number was surprising high, but I also learned of researchers' paints that release rust inhibitors ad even reform themselves to fight rusting. Another technique to slow the process of corrosion is galvanization; where a thin layer of another metal, like zinc, is coated over steel or iron. This prevents the underlying from being oxidized because it is "cathodically protected by the surrounding zinc coating." Concepts like the two parts of redox reactions, the need for an anode, cathode, and "substance" in the corrosion of a metal, and the ways paints protect metals from rust were ones that I had previously understood before reading the article.

Austin, OK. Looks good! 5 stars! MW