It was back to the lab to get a taste of how hard it can be to separate mixtures into pure substance. Using magnets, water, strainers, filters, and other chemistry supplies, we attempted to separate a mixture of poppy seeds, sand, salt, and iron filings, with mixed success. This was good practice for chemistry, since most elements don’t exist in their pure forms out in the world — we have a new appreciation for how hard it can be to successfully isolate an element. (And a new sympathy for Paul-Émile Lecoq de Boisbaudran, who must have been so ticked off when our Scientist of the Week, Dimitri Mendeleev, tried to take credit for his discovery of gallium because he’s predicted its existence on his periodic table. Gallium was also our element of the week — get your student to tell you about the disappearing spoon prank!)
Speaking of mixtures, how did all these elements get here in the first place? We traced the elements all the way back to the big bang, marveling at how energy became mass (finally! Einstein’s theory makes total sense!) and how stars were doing nuclear fusion way before the Berkeley labs got into the game.
Next week it’s all about the periodic table as we figure out how atomic theory and the periodic table of elements work together to explain everything we need to know about how a particular element will behave.