Miller,+Deanna

This article was very interesting. I’ve heard religious references to frankincense and myrrh, but never knew what they were exactly. I was very surprised to find out that they had body preservation and pain relieving properties. They were found in tombs in Egypt and preserved British war generals, but why are they not used more often today for burials? Something else I learned was the origin. I knew the substances came from somewhere in the Middle East or Africa, from the religious references, but it was interesting to find out they are both liquid like substances released from trees. They then dry to colored pellets in the sun to be used. I’m also wondering with that, if the liquid is stronger than the solid form and it could be used to mix with medicine. The most interesting finding, to me, in the article was that frankincense is like an anti-depressor. It was an interesting connection between that and the happiness/euphoria seen in religious rituals where the incense (frankincense) is released.

Deanna,

Cool beans! You are one of the few that read this article. I thought it was interesting. 5 stars! MW

REDEFINING THE KILOGRAM This article was very bland and somewhat difficult for me. I couldn't really follow the math, I haven't learned those formulas yet. I was surprised they randomly found an object that was exactly a kilogram and that its so tiny. It's unrealistic to have an object as the defining property. Different objects are heavier or lighter than others, so it would take different amounts to equal a kilogram. What was most surprising was there are 2 constants that could replace the standard, but they aren't being used. They are more accurate anyway, as the standard is losing mass over time. Another thing I learned is the Avogadro Constant is associated with the mole (another SI base unit). I don't know about the mole yet, but if it helps teach the mole concept it should be used.

Deanna, Good points! Yes the article is probably a bit confusing. The mole concept is central to chemistry. MW

CRUDE OIL The video we watched today was very educational for me. I’ve always wondered why oil was so important as a natural resource and why we didn't use other substances for fuel. But I learned that not only gasoline comes from oil; but so do other important fuels like diesel, jet fuel, and propane. We can also use components to form asphalt. The most important thing I learned in this video was exactly how distillation worked. I understood the basic concept that substances were heated to separate properties, but I didn’t completely understand how it worked. I learned that they heated substances to take certain parts and turn it into liquids. They separate at certain temperatures, and not all molecules vaporize at the same temperature. It was also interesting to learn about the more complex forms of distillation, like oil refineries, that is one big plant that separates a substance.

Deanna, Wow! You really got a lot from this video. Well written post! 5 huge stars. MW

MOTION DETECTORS In this article there were actually a few things I knew. I knew about the first type of motion detector. The first had a beam of uninterrupted light shining on a certain place, and when the light became blocked it meant there was some form of motion. I also knew about electromagnetic radiation from what we learned in class. These light sources are used in light sensors. Another thing I knew from class was that when a sufficient light is shined on an object it ejects electrons and there are many different types of lights because there are many different materials. There more new information though than old. I learned about the other two types of motion detectors. The second uses a pulse of sound waves to bounce off a source, and when it is interrupted that also means there has been motion. The third type detects warmth using infrared technology. And even though I don’t fully understand it, I learned how the eye is like a photo sensor and how it picks up light. The most interesting thing I learned was about the ‘photoelectric effect’. It really helped make it clear when they explained Hertz’ experiment. This showed that the frequency is more important when energizing electrons to give off photons. Intensity determines the amount of electrons that become excited.

Deanna, Good job! I liked the ping-pong/steel ball analogy. 5 stars! MW

WHERE DO ELEMENTS COME FROM?

During star explosions chemicals combine, forming ions and molecules. Young stars are mostly hydrogen; through nucleosynthesis and beta decay nuclei of most elements are formed.

Deanna, Well done! 5 stars. MW

EXPLOSIVE SUGAR There are a lot of things that were interesting about this article. The first is that for an explosion there are more gas as products than reactants in a chemical equations. For sugar there is 12 moles of gas as reactants and 23 as products. Explosions obviously give off gas, but I never thought about how there would be more released. Another thing I thought was interesting was all the factors that could cause an explosion, like the state of matter and the surface area of the matter. The article said the smaller the surface area the more molecules would be exposed, so it would be easier to completely burn the matter. Lastly, it was really interesting when it specified some of the small matter that are explosives. Dust from coal, plastics, and flour were just some of the materials I never would have thought could explode.

Deanna, Very well written! Good connections to class. A little late on this one. 4 stars. MW

HELIUM BALLOONS There were lots of interesting things I never heard of in this article. Something important I learned about was a buoyant force. Every object has one although its very slight, less than a pound for most objects. It's a force that acts on objects to make it accelerate upwards. It's a tiny opposition to gravity. Another important fact is that pressure is key to determining buoyant forces. Pressure decreases at higher elevations, so there are slightly more air molecules hitting the bottom of an object making it rise, than hitting the top and pushing it down. The most important fact was Archimedes Principle. This states that the buoyant force that makes an object rise is equal to the weight of a fluid being displaced. Since they are exactly equal, the object will neither rise nor sink. I'm wondering how this applies to objects that have no fluids, such as metals.

Deanna, Metals are generally pretty dense. Although a few will float on water none will float in air. They would all have a buoyant force though. Good thoughts! 5 stars. MW