Grobosky,+Ryan

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I found this article to be very interesting. I already knew that there are certain detectors such as motion detectors. This is pretty self explanatory. They go off when the sensor becomes blocked. Another thing I knew is that sonar is used to detect things in the ocean. This uses something called an echo to send a wave and when it bounces off of the target, it returns to the starting point and reveals the needed data. The last thing I knew was the other type of sensor which is the heat sensor. This uses inferred radiation to depict what is around.=====

What I did not know was the actual process with photons and electrons and how it all worked. I learned that our eye, for example is a photo sensor. It detects visible light (obviously certain frequencies only). This visible light pushes around the electrons and creates several chemical reactions in which we see. Another thing would be how Einstein figured out how each individual particle matters when looking at photoelectric effect. Also, when light is shined on a specific surface, the electrons can bounce off and shine elsewhere. The last thing that really interested me, not just in this article, but throughout this unit we are in, is that red light has the low frequency and violet light has the highest frequency. The wave on a red beam is very..wavy. While the violet has a more straight, concentrated light (because the energy is higher) and shows up almost as a straight line. I enjoy these articles. They are very interesting and are fun to read!

Ryan, Well written!!! Excellent post. 5 huge stars! MW

__Helium Balloons Sulfur Hexafluoride__
This article was interesting and I did learn some things. First I will start with the things I already knew. I knew that helium was less dense than the surrounding air. Therefore it will rise up. I also knew the higher you go up in the atmosphere, the lower the pressure of air. One last thing is that newtons are to measure force not grams or kilograms. Some things I did not know are that the force that drives the helium balloon upward. We all might think that that is supposed to happen, but without this specific force, the balloon would go down because of the force of gravity. This force that brings the balloon is called the buoyant force. This force is very small for it can only lift about 0.0028lbs. Another thing I did not know is that the buoyant force is equal to the weight of the fluid. Whether it is air, water or whatever. Another thing would be that a helium balloon deflates faster than one filled with regular oxygen. This makes sense but I never really thought about it. This is because the helium leaks out pretty quickly and oxygen and nitrogen rush in the balloon. Also, one more thing I found interesting, a balloon filled with sulfur hexafluoride will, in fact, expand instead of deflate. This is because not many of these molecules leak out while still the same oxygen and nitrogen rush in. Thus, making it grow instead.

Ryan, Good post! Very thorough. 5 buoyant stars! MW

**__Dust Explosion__**
The article “Dust Explosion” was about how big business owners that own plants and huge factories have a lot of dust laying around. This article said that there was a massive explosion in a sugar plant in Georgia that occurred because of the dust and sugar. Who knew dust or even sugar could be flammable? I mean, dust is everywhere and you eat sugar. Sugar is a substance in many foods that most humans consume. This is mind blowing. It also said that this explosion can occur from even something as small as static electricity which can ignite something (such as sugar and lead into dust) and ,in the air, form an explosion. Also, this is like a chain of explosions, not just one. There could be an explosion somewhere by accident by something, it can ignite the dust, and it shoots in rounds. The article referred to it as “rapid fire”. All of this information is going to the CSB, or the Chemical Safety and hazard investigation Board, and the OSHA, or the Occupational Safety and Health Administration to be reviewed and debated upon. The smaller the combustible particle, the more surface area there is available relative to weight. Therefore, less energy is needed to ignite it and it will burn quicker.

This article really surprised me. It makes sense that when manufacturing products and using materials to do so, they break down into smaller particles. These particles can be set on fire very easily and it can create an immense explosion. I really think that the CSB or the OSHA should crack down on this and make an effort to control it better. I did not know that sugar, or dust for that matter, were flammable. This is news to me, but I do understand why. Once those little particles get in the air, the oxygen is what makes them combustible. Very interesting.

Ryan, A very thorough post. The right mixture is indeed scary - hence the whole idea of stoichiometry. OSHA is definitely investigating this tragedy! 5 big stars. MW



__**Mole Day**__

The mole is a measurement that is measured by weight. The mole is represented by a certain number. That number is 6.02x10^23. This number came from Amadeo Avogadro. It was named in his honor by a French scientist in 1909. its value was first estimated by Josef Loschmidt, an Austrian chemistry teacher, in 1895. The mole, which is abbreviated mol, is the SI measure of quantity of a chemical thing, which can be an atom, molecule, formula unit, electron or photon. One mol of anything is just Avogadro's number. The real SI definition is: The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12.

I also found the molar volume to be interesting. This is the volume occupied by one mole of a pure substance. Molar volume depends on the density of a substance and, like density, varies with temperature due to thermal expansion, and also with the pressure.

Ryan, Awesome post. Very thorough! 5 moltastic stars!! MW

__Where do elements come from?__ There was a huge explosion that happened a very long time ago. Some refer to it as the big bang. From this giant catastrophic event which started life and the solar system as we know it today, many stars were born. These stars contain one basic element which was the start of the others. This element is named hydrogen. From hydrogen, a lot of fusion took place to form beryllium to a carbon nucleus and then the popular one, oxygen. These fusions have a name, nucleosynthesis. After successive fusion reactions, nuclei of most elements lighter than iron can be formed. In stars that are less massive than the sun, the only reaction that takes place is the hydrogen to helium one. In a star, there are two big forces taking place. One, is the star's own gravity trying to make everything as small as possible and the other one is all of the fusion taking place inside which is pushing outward. When stars have lived their life and the fusion is over, the star will most likely explode causing something called a supernova. Now this is where the new elements are formed that have more mass than iron. These form a dust cloud around where the star used to be. This dust cloud is called an intersteller cloud. How? Well, this is called the S-process. This is when a new nuclei is formed. An iron nucleus has to capture neutrons. This nuclei can be stable or radioactive. If radioactive, this means that another element is possible to form. Another process is the R-process, which is much faster with the neutron capturing. This happens during the explosion unlike the S-process which occurs inside a star. This is all really interesting to think that everything we see and live in and live around came from one explosion. Something triggered that and science tells us. Hydrogen was the first element to create everything else. This is all very cool and I like learning about space and how things got here. It's really beyond belief.

Well written, good summary. I agree it is hard to believe that all of what we know was born from stars. 5 stars! MW

__Redefining the Kilogram__
This article was pretty interesting. There were a couple things that I didn't quite understand though. It said that the kilogram is the last unit of measure that is still defined by a physical artifact rather than an unvarying physical property of nature. I am not sure I totally comprehend that right. Anyway it also goes on about how there are only 90 copies of this international prototype that exist throughout the world. Although, the official one is in a vault in Maryland. There are also two different kinds of constants that are said to change the definition of a kilogram. Planck's constant or Avogadro's constant. Both dealing with the energy in matter relating to mass. Planck's method seems simple compared to Avogadro's. Planck's is basically an equation you plug numbers into dealing with the speed of light and frequency while Avogadro's is using some type of measurement that we have not learned yet (mole). I hope you can clear some of this up in class sometime because I was really confused towards the end of this article but I am interested in learning what it means to calibrate the prototype with the new definition. Even though it somehow is retained as the same prototype and the kilogram is the same..?

Ryan, Great post! We will explain the mole for sure!! MW

__**Crude Oil**__
Crude oil is a yellowish color and is used in many ways. For example, in diesel fuel, oil, kerosene etc. It is a mixture of different hydrocarbons. When separated, hydrocarbons vaporize when heated at different temperatures. Then they cool and condense. It is flammable so it has to be heated by a furnace or a hot surface. This is all called Fractional distillation. Crude oil cannot be used as a mixture and by itself it is almost worthless. Large industries do this often with their huge distillation towers and big plants.

Ryan, Good points. BTW crude oil is black not brown when it is pumped from the ground. MW

__**Lead**__
I found this article very interesting. I always wondered why people licked their pencils and basically ate lead. Now I have an idea why. The article says that lead composes of a sweet sensation. We all know little kids love sweets. Lead is used in ink, some candy, and even chile pepper. However, lead is very toxic and could be dangerous if ingested. This can cause behavioral problems, stunted growth, kidney damage, mental retardation, and learning disabilities. Lead was also used in paint before it got banned because of its hiding power and corrosion resistance. In conclusion, lead, although is or was useful in some aspects, is also very harmful if used the wrong way. So think about what you are really getting yourself into next time you get that pencil close to your mouth.

Ryan, Generally good. 5 stars. BTW pencil "lead" is actually graphite a form of the element carbon. So chomp away! :) MW