Villarose,+John

__//The Chemistry of Lead Poisoning//__
I read the article on lead poisoning, and it was very interesting. Lead can be a very dangerous substance when consumed in significant amounts. Paint used to put people at risk of lead poisoning due to lead-based paint. Yet now, after lead-based paint was banned, it is discovered that dangerously high levels of lead can be found in candy. However, rather than in regular candies, it usually occurs in Mexican chili-based candies. While the risk for most Americans is low, many people (including myself) have tried these candies, and although most American stores refrain from selling them, they are still easily found in states such as California. If the element of lead in common products is not controlled, many people could be at risk.

John, I think I've eaten some of those candies too. I especially like the tamarind candies :( . MW

=//__Distillation of Crude Oil__//=

The video on the distillation of crude oil informed that oil itself has no purpose in its original form. Without separating the parts of crude oil through the process of distillation, nothing can be done with it. The crude oil was distilled through what seems like a somewhat complicated process, which is mainly based around heating the crude oil. However, once separated, oil is one of the most important resources in the modern economy. While its main use is gasoline, which most people are aware of, I found out that it is also used in things such as polyester.

John, Looks good. 5 stars. MW

=**//__Redefining the Kilogram__//**=

This was, to say the least, a very complicated and somewhat confusing article. The kilogram is one of the few base units of the International System of Units. The original kilogram is defined by a small piece of metal from 1889. I was shocked to learn that it is kept under such strong protection: in a sealed vault in France, along with multiple copies of it. However, despite being guarded so heavily, the prototype kilogram has still lost 50 ug over time. I was slightly confused by the section talking about Avogadro’s Constant and Planck’s Constant, but it appears that they are now trying to redefine what exactly the kilogram is due to the size change.

John, Right you got it! MW

=//__Where Do Elements Come From?__//=

Almost 1000 years ago, a star exploded in a supernova, releasing many elements into space. It was the first witness of a supernova recorded. In a star, gravity causes the core to collapse upon itself, resulting in an explosion, through which elements are released into space. According to the article, all elements come from the base element of hydrogen, which young stars are made up of. The fusion of multiple nuclei creates new elements, which I found fascinating, as I had always thought that all elements were separate from the others, with no one existing for longer than the rest. Through the S Process, an iron nucleus can collect neutrons, which may or may not change the element, depending on their radioactivity. If an element is radioactive, it will at one point change into a separate element, while a stable element will remain so.

John, OK. Cool deal. 5 stars. MW

=**//__Mole Day__//**=

"What is a mole's favorite movie? The Green Mole!!"

Sorry, I liked that one. While very odd and somewhat cheesy, the Mole Day site was pretty informative. The National Mole Day Foundation was founded on May 15, 1991. The foundation currently gives out awards (such as the Mole of the Year award) annually. On the scientific side, the site is made to honor the "mole," also referred to as Avogadro's number, named after the Italian scientist Amadeo Avogadro posthumously. The uses of the mole were technically discovered by Stanislao Cannizzaro in 1858, two years after Avogadro's death. The number, 6.02214199 x 10^23, is now commonly used for scientific purposes. With all the little jokes of mole-related humor filling the site, it was distracting to try to get to the actual information, but the information was very important, as I had previously believed that Avogadro was the only scientist involved with the mole's creation.

"Moleskito: //a tiny molelike creature with wings which drinks the blood of anyone who doesn't remember when Mole Day is."

John, Great post. funny, scientific and well written! 5 moletastic stars. MW//

=**//__Dust Explosion__//**=

This article is about explosions that occur in plants due to combustible dust particles which form throughout the plants being set off. It states that almost all material, when broken down into small enough particles, becomes explosive. In the specific case of the article, the combustible dust was broken down from sugar, which before I never would've thought to be explosive. I do think that this seems to be easily preventable. Yes, the dust is combustible, and will remain so. However, according to the article, approximately an eighth-inch of dust will create an explosion, so if the plants are ordered to be regularly cleaned, the situation would probably be much less drastic.

John, It makes you wonder if nearly everything is flammable in the right proportions! 5 stars! MW

=//__Sulfur Hexafluoride__//=

Before reading this article, I had already known what sulfur hexafluoride was composed of: one sulfur atom and six fluorine atoms. I also knew that sulfur is used in making matches and gun powder. I did not know about the first hazard of breathing in helium and hexafluoride gas: oils and toxic hydrogen fluoride gas. However, I was aware of the second hazard: the fact that the gases do not provide oxygen, which the body depends on. I was surprised when it sated that the gasping reflex is not triggered by the lack of oxygen in the blood but by the buildup of carbon-dioxide in the bloodstream, as that's never really something I thought about. Another new fact I learned from the article is that the molecule of sulfur hexafluoride is symmetrical, and that the polar bonds in it cancel out to create a nonpolar molecule. This article brought up a lot of things that I just wouldn't tend to think about with something as simple as balloons.

John, Good thoughts and well written - as usual! 5 huge helios stars! MW

=**//__Motion Detectors__//**=

I was previously aware of the first technique used in motion detectors: the blocked light beam. Similarly, I knew about the second technique, which is the echo method that detects reflection pattern changes. However, the third technique was new to me, involving infrared radiation sensors. After listing the techniques, the article went on to mention how visible light moves the electrons in a "cis-retinal model" in the eye, which I had not known previously. The original observation of the photoelectric effect by Heinrich Hertz in 1887 was also new. Towards the end of the article, it mentioned how Albert Einstein had won the Nobel Prize in physics in 1921, which I had learned about prior to reading it.

John, OK. Looks good! 5 stars. MW