February 13^th is Étienne François Geoffroy's birthday. Geoffroy was a French physician and chemist who was the first to arrange the known elements into a table based on their chemical affinity to each other.

Anyone who has ever mixed two items together knows some things combine better than others. In chemistry, two different chemical species' affinity is a property that shows how likely a chemical reaction will occur when mixed. Reagents with strong affinity are more likely to react with each other than reagents with little affinity to each other. Geoffroy's table had a series of reagents across the top with other reagents with high affinity with these elements listed below. This table became a standard table for 18th Century chemists until the end of the century when it was shown the amount of a reagent drove the reaction.

Find out what else occurred on this day in science history.

So, the other day I found myself in a hotel room with a frozen pizza and a stove, but no oven. I did what any hungry scientist would do. I set out to determine whether or not it was possible to cook a frozen pizza on the stove. In order for the experiment to be a success, the pizza had to be good enough to eat. Well, also I would have considered the experiment a failure if there had been a fire. That is not generally a condition of failure in my projects, but when I'm on the road I'm a little less of a pyro.

Anyway, I wrote up the project in terms of the scientific method because I think this is the sort of everyday science that people can relate to more easily than an experiment using hard-to-pronounce chemicals... Let's cook pizza!

My daughter's favorite science project is making rubber eggs. You only need two ingredients for the rubber egg project, an egg and some vinegar. You'll get somewhat different results depending on whether you start with a raw egg or a hard-boiled egg, so try both! The project is safe enough for young kids and doesn't make a mess (unless you throw the egg hard), plus the resulting egg can be used as a bouncy ball. Try it out...

Have you ever wondered why some meat starts looking brown after a few days in the meat case at the grocery store, while other meat stays fresh-looking longer? Some meat is packaged in an atmosphere high in carbon monoxide, as opposed to normal air. The carbon monoxide binds to the myoglobin (a protein) in the meat to cause it to look the pink color most of us associate with fresh meat. The chemical reaction that causes the color fixation doesn't present a health hazard, but there are concerns about consumer safety because people buy meat according to how it looks. Meat that has been packaged in a carbon monoxide-rich atmosphere will continue to look pink past the point when it should be sold. Untreated meat gets darker in color as it stays on the shelf. Of course, there are other indicators of freshness. A slimy appearance is a giveaway of decay, as is bulging packaging from the gases produced by bacteria. If you could smell the meat, you'd know whether or not it's good, too.

Anyway, it's an interesting application of chemistry in our day-to-day lives. There's no labeling on meat to let you know whether or not carbon monoxide packaging has been used, but you can still figure it out. The next time you're grocery shopping, take a look at the meat that has been marked down because it's close to its sales date. Has the meat started to deepen in color and become more brownish? Is it a vibrant pink? If it never changes color, you can be sure the color was fixed.
Rigor Mortis Chemistry | Chemical Composition of Blood