The site about Avogadro's Hypothesis was an effective reminder of how vital the mid-to-late nineteenth century was in terms of European Chemistry. I also generally like these multi-disciplinary science sites, with interactive questions, engaging articles and images... even if some are hokey.
The site on Understanding the Mole concept brought to mind my high school chem honors class project designed to help us conceive of the vastness of a Mole. Our teacher explained Avogadro's number and how to use it similarly to the way we discussed in class, then our final project for the semester challenged us to demonstrate our understanding in a pretty cool way. We each had to pose a question whose answer would somehow involve Moles of something, then we had to do the math to demonstrate the problem, and make some kind of graphic presentation. My question was: How long would it take for the city of Las Vegas to use a Mole of lightbulbs?
BARIUM
My experience with Barium was similar to several classmates' impressions of calcium as a chalky, white substance. When I've had radiography performed on my upper GI system on a couple of occasions I had to drink absolutely gross Barium Sulfate mixed with Tang (in 1992) and some other flavoring a few years ago. It turns out that Barium is radioopaque, so on an x-ray it shows up, demonstrating to technicians where strictures or other troubles appear in the esophagus, stomach and duodenum. Although Barium can be toxic, it is not absorbed by the digestive tract as it is not water soluble, and so is completely eliminated by the body following this kind of diagnostic test.
Barium is also used in the petroleum industry, apparently, as an ingredient in "drilling mud" which is basically injected into to earth to ease the drill's pathway.
Barium Carbonate is an ingredient in rat poison.
So far this post seems to be giving Barium a bum-rap, but this alkaline earth metal, (which is highly reactive with air and therefore doesn't appear in its elemental state) does us a lot of good as well.
For example, the fact that it burns easily in air led to Barium Nitrate's use for green colored fireworks. Barium peroxide is great for welding, and Barium Titanate was recently proposed as a possible substance for use in next-generation electric car batteries.
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2 comments:
hey, i'm really glad, since you had to have your gi checked out, that it's not the 1940's anymore! (no carcinogens.) still sounds like a pretty yucky breakfast.
I can empathize with your experience drinking Barium. I had an upper GI test earlier this year and trying to down the stuff was like trying to swallow a liquid sock. It was fun the way they kept rotating the table around it make it coat by GI tract, though.
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