Cable,+Matthew

I read the article Coins and Chemistry. I thought that this article was very interesting. One interesting thing that I learned is that during World War II they make steel pennies to conserve copper for the war efforts. Another interesting thing was that in 1965 they stopped making coins that had silver in it. So quarters no longer contain silver. Finally the last interesting thing that I learned was that new pennies are made of zinc with a copper coating around the outside.

Matt,

OK. Well done. You hit the highlights! 5 stars. MW

Redefining The Kilogram

In Redefining the Kilogram there were a lot of interesting topics. One in particular was that the kilogram had lost wait from the last time it had been weighed. Even thought it was a very, very small amount it still affects the accuracy of it. Another was that it was kept in a vacuum to prevent it from losing weight. Finally the most important point was that it was the last of the SI base units that is still defined as a physical artifact.

Matt, OK. Pretty basic but you answered the prompt. 5 stars. MW

Crude Oil

I think that this movie shows a lot about how useful oil is. I did not know that so many fuels could come from just a little bit of crude oil. Also, it is very easy to separate all the fuels and it does not take a lot of time. The most important point that i learned was how important drilling for oil is. It provides so much energy and money for the US. Another interesting fact is that the benefits would outweigh the risks of drilling for oil.

Matt, Your last point is no doubt debatable. How did you derive that from the video?? 4 stars. MW

Motion Detectors

In the Motion Detector Article there were many things that I learned but there were also some things I already knew. Some examples were that I already knew motion detectors used sound waves and infrared to figure out that there is movement. Another fact I knew was that glass could block the infrared motion detectors. Also I knew that sinks use these motion detectors to turn on the water. Some facts that I did not know were that motion detectors could go off so easily when the kid was sneaking to his room. Also, i didn't think that infrared detectors could detect stuff through milk carton plastic. Another that I did not know was that just a little bit of heat could set infrared sensors off.

Matt, OK. Most use light not sound but looks good. 5 stars. MW

Chemical elements

Chemical elements come from super novas made inside from transforming to different elements from heat. Eventually the star explodes and they end up on Earth.

Matt, A little sparse on content but OK. 5 stars/

Sugar As An Unusual Explosive

==== The article ‘Sugar an Unusual Explosive’ was about an explosion that took place in a sugar factory and how. One thing that relates to chemistry is the sugar can only explode if it is a dust and has an ignition source. One interesting fact is there’re many other dusts that explode for the same reason, like flour. Finally, the most valuable point is for a dust to explode it needs a lot of surface area ====

Matt, OK. Looks good. A little late though. 4 stars. MW

Helium Balloons

I think that this article was interesting. An important point that it mentions is that helium rises because it is less dense than air so it has to rise. Next is there is a buoyant force acting on every object but you cannot feel this. The most important point is the higher up you are the lighter the air. This is important because up high the air is thinner and helium won’t go any higher.

Matt, Looks like you missed a point. 4 stars. MW