Category Archives: Chemistry

Ban Dihydrogen Monoxide!

I first saw the following text in an e-mail back in 1997. For those of you who have not yet read it, or have seen it and may have forgotten about it, I thought that it might be fun to post it here. It’s a good reminder of the fact that there really are no totally harmless substances. Find out more about the origin of this “warning” at Snopes.com:

BAN DIHYDROGEN MONOXIDE! THE INVISIBLE KILLER!

Dihydrogen monoxide is colorless, odorless, tasteless, and kills uncounted thousands of people every year. Most of these deaths are caused by accidental inhalation of DHMO, but the dangers of dihydrogen monoxide do not end there. Prolonged exposure to its solid form causes severe tissue damage. Symptoms of DHMO ingestion can include excessive sweating and urination, and possibly a bloated feeling, nausea, vomiting and body electrolyte imbalance. For those who have become dependent, DHMO withdrawal means certain death.

Dihydrogen monoxide:
* is also known as hydric acid, and is the major component of acid rain.
* contributes to the “greenhouse effect.”
* may cause severe burns.
* contributes to the erosion of our natural landscape.
* accelerates corrosion and rusting of many metals.
* may cause electrical failures and decreased effectiveness of automobile brakes.
* has been found in excised tumors of terminal cancer patients.

Continue reading Ban Dihydrogen Monoxide!

Bubble-ology

Bubbles and balloons can be used to teach the following concepts: Bernoulli’s principle, color, images, light and surface tension.

  • Ms. Cheek 4th grade teacher from Kennesaw, Georgia, has a list of bubble-related web pages on her classroom website.
  • The Nueva School has a list of links related to bubbles and ballons.
  • The Exploratorium provides information about bubbles, recipes for bubble mixtures, as well as a “bubbliography” and a list of internet resources.
  • National Chemistry Week Open House

    For those of you in the Princeton, New Jersey area:

    The Princeton Local Section of the American Chemical Society and the Princeton Chemistry Department will sponsor a National Chemistry Week Open House at Princeton University’s Frick Lab on Friday, October 24, from 7:00-8:30 pm. The program will start in the auditorium, just across the foyer from the main entrance. All community members 6 years old and up are invited. Children ages 6-12 must be accompanied by a responsible adult.

    This year’s theme is “Chemistry in Earth’s Atmosphere and Beyond.” The program will include short presentations with demonstrations in the auditorium and hands-on activities and demonstrations in the laboratories downstairs. Activities will be supervised by American Chemical Society members and Princeton University staff and students.

    Topics include chemistry in space, how gases behave, the structure of the atmosphere, chemistry of oxygen, chemistry of carbon dioxide, making clouds, pollution and how it travels, flight and space flight, the greenhouse effect, the ozone hole, and many more.

    Please register with Kathryn Wagner, Princeton University Chemistry Department, by Thursday, October 23. E-mail kmwagner@princeton.edu or call 609 258-2937 and leave your name, the number of people, and the ages of any children you are bringing.

    Why Do Leaves Change Color in the Autumn?

    Forensic Science

    There are many different forensic science activities that can be found on the web. Here are just a few examples:

    • Using the same method I mentioned yesterday (paper chromatography), students attempt to identify the pen that was used to write a “ransom note” left at the scene of a crime (Auburn University Science in Motion).
    • This description of the ransom note chromatography “Crime Lab” activity from the University of Arizona has a nice set of teacher notes accompanying the experimental procedure.
    • Classroom capers” describes the following analyses of evidence collected from the “crime scene”: hair matching, footprint matching, handwriting analysis, ransom note chromatography, fingerprint recording and analysis and fibre analysis.
    • There are even methods of lifting fingerprints from a ransom note, as described here from Queen’s University (suggested for 9th grade and up).

    Candy Chromatography

    This is a fun project that can be altered to suit all different age groups. I have done this in a 3rd grade classroom. Each student got to prepare their own samples. It was a big hit!

    This activity involves the use paper chromatography to separate the colors/dyes use in candy coatings of a Reese’s piece or an M&M. We choose to use the “dark brown” varieties of each candy and had the students compare the components by chromatography. It was a great way to introduce “mixtures.” Before doing the chromatography with the candy coatings, we introduced students to the concepts of chromatography using food coloring (both individual colors and mixtures of the food dyes).

    Here are some references for related activities that I found on the web:

    – from Science Discovery
    – from Auburn University Science in Motion

    …and there are even methods of dye extraction and separation for more advanced students (high school or college).