Moyer,+Lauren

Coke and mentos- post 1 I read the article about coke and mentos and what happens when the two mix. Something that really interested me when reading the article was that a newly opened bottle of soda can go completely flat in a few hours due to a process called effervescing. Effervescing is the undissolving and bubbling of extra co2. The reason the mentos reacts with the coke in such a way is because of the mentos' microscopic bumps and edges inside that have pockets of air that react with the co2 bubbles in the soda. When the candy is dropped to the bottom of the soda, the pockets of air are released that produce more and more gas. Another reason that mentos react is because of a chemical found in it called gum arabic that releases more carbon bubbles. The reaction is based on the inside of the candy, not so much the chemicals.

Hi Lauren! I thought your article was very good. I never knew that soda could go flat that fast. Good job with decribing the whole process of the mentos reacting with the coke and the reaction with CO2 bubbles in the soda. Ben Raver

Lauren,

Wow! You really picked some great chemistry and chem vocabulary out of this article. Well done! 5 stars. MW

Redefining the Kilogram- post 2

This article was about the SI unit kilograms and how the international measurement has lost atoms in the millions. This could serve to be a problem in the future because other SI units are based on the kilogram too. When reading the article I found some interesting facts right of the bat. One of those facts was that the kilogram is the last of the SI units that is still defined by a "physical part of nature". Another thing i found very interesting was the core goup of people this change would affect. The goup most affected are to my suprise meterologist. My MVP fact and my last interesting fact that i found was the fact that there isnt just one ofr two prototypes but 90 throughout the world. I found it very interested and would like to even learn more about the prototypes and if they to are sheading atoms; just at maybe a different rate.

Lauren, Good question on the prototypes. They are systematically compared to the original but what is done if the prototypes lose mass?? I don't know. Well done. 5 stars. MW. PS please use spell check. :) %Proxy-Connection: keProxy-Connection: keep-alive Cache-Control: max-age=0 -alive Cache-Control: max-age=0

Crude Oil- post 3

crude oil is dark brown and found near the earth'sProxy-Connection: keep-alive Cache-Control: max-age=0 rust. It is made of carbon and hydrogen. Each part of the oil have different boiling points. The oil that has "tighter" atoms have a higher boiling point then the ones that say evaporate at 85 degree celsius. The oil that then has the higher evaporation point is then separated with a process called fractional distillation. With what is left of crude oil is the condensed and heated. Today we use crude oil for plastics and fuels.

Lauren, Where did the the term "tighter" come from? In the video we saw that larger molecules boil at higher temperatures. What is your most interesting point? 4 stars. MW

Motion Detection- post 4

One thing I knew prior to the reading was the different kinds of detectors. When saying i knew the different kinds i only knew of the light sensitive one and the reflective one. I didn't know that there were others and how those two worked. By reading this i grasped a better understanding of how the sensors work and the different types. Another thing i knew was that the eye serves as a photo sensor. I didn't know that there where many chemical reactions taking place in the eye for the brain to receive the message from the retina. Something else I knew from the article was that many motion detectors are used in every day life and not just for protection reasons on someone's home. Motion detectors are found in everyday places like elevators, and automatic doors. The last thing I found that was new and very interesting to me was Albert Einstein worked on the photoelectric and won a noble prize for his work. To me to not even be well known for working on that and still win a noble prize is astonishing and very interesting.

Lauren, OK. Well done! 5 stars! MW

Where Do Chemical Elements Come From- post 5 25 word abstract:

During star explosions chemicals are released. Elements travel to earth and other planets and form everything seen. Scientists believe interstellar clouds formed stars planets.

Lauren, OK. 5 stars. MW

Sugar an unusual Explosive

One thing that I found very interesting about this article was the fact that sugar, a common substance that I ingest on a daily basis when grinned could blow up! What i also find interesting is why it doesn't blow up when we eat it. When we eat it the energy is stored and the reaction occurs at a slower rate. The reason it exploded is due do to a build up in the air and the speed of the chemical reaction compared to the body. Another thing I found interesting was the size of an average sugar particle was as thick as a fingernail. I thought that they were much smaller than that to be honest. When I looked at my fingernail thickness I thought that a sugar particle would be about half of it. The last thing that I found very interesting was that dust from coal, flour, metals, plastics, and wood can explode in all the right conditions. With all of these substances combined there have been over 350 explosions. To me that is a very high number for a reaction that I had no clue could even occur.

Lauren, OK. "ground not grinned". your connections to class are a little cryptic - but OK 5 stars. MW

Helium Balloons- 75 words

Helium balloons have mass but continue to rise because off it's density. The buoyant force is what causes the balloons to not drop toward the ground and actually float above us. I found it very interesting that this force is only strong enough to lift .0028 pounds for every liter of air the object displaces. That is an extremely small number that seems like it couldn't lift anything: not even helium. What I also found interesting was that the buoyant force is still there even for object like a human. It's just so small that you would never notice. The example that they gave included a 154 pound person that displaces 70 pounds of air. With this ratio they were able to determine the amount of buoyant force in the surrounding air. The density plays a role because the buoyant force is exactly equal to the weight of whatever that it displaces. I found this article to be very interesting in general and learned many new things.

Lauren, Clearly define your VIP's and MVP. BTW a 154 lb person does not displace 70 lbs of air! 4 stars. MW