Do-It-Yourself Chemistry Flame Tests скачать в хорошем качестве

Do-It-Yourself Chemistry Flame Tests

http://chemin10.com Flame tests are one of the standard laboratories in high school chemistry. In this video, I show you how to do flame tests yourself, at home, using a few simple household ingredients. These ingredients are: Flame source (I use an alcohol burner) Paper clip attached to a cork (to serve as the nichrome wire) Denatured alcohol (or rubbing alcohol) Various metal salts In this video I used: boric acid (sold in small hardware stores as roach killer) table salt (NaCl) salt substitute (pure KCl, found in the grocery store spices aisle - NOTE: read the labels carefully) copper (II) sulfate (from the Thames and Kosmos C3000 Chemistry Kit) I dissolved a little of each solid in denatured alcohol to make it easier to handle in the flame. Copper (II) sulfate is not soluble in alcohol, so this didn't help much. You may just want to burn the salt crystals directly in the flame. It may be difficult to scoop up a few salt crystals with your wire device if you do the latter. Also, be careful not to drop crystals onto the flame source. Otherwise, all of your flames will be the color of the dropped crystal. Make sure to burn all of the salt crystal off and/or clean the wire when changing between salts, or your colors will be contaminated. The Chemistry Behind It When sufficient energy is added to an atom, such as by heating in a flame, its electrons are excited to higher energy levels. When these electrons relax back to lower energy levels, they emit light of a wavelength equivalent to the energy difference between these energy levels. Wavelengths of electromagnetic energy emitted in the visible spectrum are seen as bands of colored light. With each type of metal salt, one color predominates and that is what is seen in the flame test. If you are looking for chemistry help, or want to be the star in your chemistry class, then consider a membership to Chem in 10. We teach high school chemistry in 10-minute easy-to-understand video lessons with interactive quizzes. In addition, we are adding do-it-yourself chemistry labs weekly. Love science, but not taking high school chemistry? Now is the perfect time to enroll in our online chemistry course. The only prerequisites are a proficiency in algebra, and a desire to learn chemistry! Get your hands dirty in our do-it-yourself chemistry labs and your mind growing with our online chemistry videos and interactive worksheets and quizzes. http://chemin10.com