McDaniel,+Evan

I read an article on coins and chemistry. I found that coins have almost no value, as far as the metals (alloys) used to make them go. I found that they use different metals to make them mostly so they can survive the wear and tear of everyday use. Which I think is smart but then again they have no actual value, so your not guaranteed that it will worth anything. What coins are made of is very important to how a vending machine works. It measures the coins weight, measures the diameter and is passed through poles of a magnet. If it is magnetic then it is rejected because no U.S. coins are magnetic with the exception of one penny made in the 40's for one year. Which all in all, I think is very interesting. I found that that is why coins like canadian pennies won't work with a vending machine.

Evan, Looks good. I liked the vending machine thing too! 5 stars. MW

Redefining the Kilogram

I think that using something that is not an actual physical representation to define a kilogram would be an excellent idea. So if 5.0184515x10^25 ^12 C atoms does equal a kilogram we could never loose that number and we can always have a way to check with it out it ever changing for the rest of time! Which is my favorite thing about this article. I also like the fact that that we have something that can actually be measured and be kept constant in nature, which I didn't even think was possible when we discussed this in class. My last comment is how can you let the actual kilogram, the real one that is used to define it, gain weight? It seems like they didn't try hard enough to keep it from gaining or losing weight.

Evan, OK. I agree that we should just go ahead and redefine the kg. 5 stars. BTW it's "losing" not "loosing." MW

Crude Oil

I did not know that crude oil was separated through distillation. I also did not know that it can distilled more then one time and collect many different liquids from that. I knew that diesel was similar to gas and not as flammable, but I did not know that it was made from the same thing as gasoline. I think this is useful to our class because we can do this so we can learn how to distill various things.

Evan, OK. Pretty basic but 5 stars! MW

Motion Detectors!

I already knew that motion detectors exist! I also knew that they can turn lights on by detecting motion and that there is more then one type of motion detector! What I did not know was that there were three specific types of motion detectors, ones that use a light source aimed at a photo sensor, ones that send out pulses, and ones that detect infrared radiation! I also learned that a photo sensor is any device that senses light! I never would have guessed! I also never knew that Hertz was named after the german scientist Heinrich Hertz! Who would of known!

Evan, Good connection with Hertz! Amazing. 5 stars. MW

Where Do Elements Come From?

Most of the first 26 elements are in stars, when released in to space they form different elements and man different ions can be formed.

Evan, I think you meant many not man. 5 stars. MW

Sugar an Unusual Explosive

I think this article was interesting because I think it's funny how such a common item such as sugar, can be turned in to something deadly. This is like what we did in class with the lykepodium powder and the pumpkin. It increased surface area that could burn ( or explode) and was in the air ( like the sugar dust). Also we have been working with sugar ( C6H12O6) in class lately and this lets us know more about the substance and what it can do. Plus this is a chemical reaction which we spent a good sum of time working on.

Evan, OK. 5 stars.

Helium Balloons

An important fact in the article is that helium balloons float because they are less dense in air, just as wood is in water. Another important thing in the article is that there is a buoyant force that lifts on everything in air. So if you want to know your true weight you would have to go in a vacuum where there is no air to lift up on you. The most important thing is that more atoms are hitting the bottom of an object then the top. That's because air gets less dense as you travel up from sea level. So a not very dense item would be lifted from the more atoms hitting the bottom then on the top.

Evan, Good job! Well written. 5 stars. MW