Sulfur

October 6, 2011 in Elements

On Friday, November 28th, 2008, the fifty-nine students of the combined English and French fourth grade classes taught by Ms Reavell and Ms Breton at École F.A.C.E. School were exposed to fifty minutes of stench-free sulfur chemistry and bonded with mercatpans thanks to university students Jess Aylsworth (BA Art Education, Concordia U), Cindie Eugene (B.Sc., U. Montréal), Tanya Godina (MSc., U. Montréal), Maya Grubisic (BA Art Education, Concordia U), Zac Kenny (BA Art Education, Concordia U) and  Sixian Lin (B.Sc., U. Montréal).  Tanya and Maya started a bilingual discussion on sulfur, which from the past MLP on the essential elements, the students remembered was in eggs and in the smell of rotten eggs.  They soon realized that sulfur compounds are also responsible for the smell and taste of grapefruit, onion and garlic, as well as for the tenacious odor of skunk.  At this point, rather than make stink bombs, the discussion curled to hair, which has sulfur too; however, it is bonded to other sulfur atoms in the bridges between hair fibrils that are responsible for hair’s toughness and abrasion resistance.

Three volunteers darned proper lab safety gear and joined Cindie and Sixian in the performance of an experiment in which Professor Lubell’s hair served as straight starting material which was curled by the chemical process in which the sulfur-sulfur bridges in hair are broken, rearranged and reformed by the use of a two-step reduction-oxidation process.  Once on the subject of hair and bonds, we could not help ourselves from playing with the weaker bonds in hair (i.e., hydrogen and salt bonds).  Armed with curling irons, Jess, Tanya, Maya and Zac rearranged hydrogen bonds and shuffled salt bridges as they straightened out some curls and spiraled up some others on the heads of four more student volunteers.

Finally everyone got into the act of reshaping fibers by bond shuffling, by exploiting the thermal plasticity of polyester.  Employing rubber bands to tightly bind their own handkerchief-sized fabric samples around stones, marbles and blocks, the students had just enough time to staple a name tag to their sample before placing the bound textiles into boiling water for 5 minutes.   After cooling the fabric, the bound objects were removed, yet their impressions remained as memories formed from the shuffling of weak chemical bonds.  The students left thankful to learn about sulfur and bonding, without the stench.

Much thanks goes to team sulfur for showing us that mercaptans can be fun, to Valerie d. Walker for teaching team sulfur about the joys of thermal plastic textiles, and to Peter for helping to tend the big pot of boiling water.

 

Magnesium

October 6, 2011 in Elements

Brilliant white light illuminated the debut of our 3rd year of MLP fun, as flames of magnesium (Mg) fire brightened the 4th grade students in Ms Reavell’s class on Friday the 13th of March, thanks to Team Mg composed of Zac Kenny (BA Art Education, Concordia U) and Sixian Lin (B.Sc. U Montréal).   Requiring more heat than the match used to start a wood fire, an alcohol burner was used by Sixian to ignite magnesium metal, which is protected from the oxygen in air by a thin layer of its oxide.  Watching the burning magnesium, the students were fixated on this oxidation process that produces magnesium oxide, the latter when poured into water formed magnesium hydroxide “milk of magnesia”, a medicine used commonly as a laxative and antacid.  The students were reminded that magnesium is the metallic ion at the center of chlorophyll, and is an essential element for plant survival commonly added to fertilizers.   Moving from the lab to the classroom, where tempera paints and Epsom salt (magnesium sulfate from the mineral Epsomite) were waiting, the students were engaged by  Zac, who explained how to experiment  with the effects of the magnesium salts on the wet water colors.  As the students painted and salted, the applications of Mg were further enumerated in discussions that touched on uses in automotive and truck components, because Mg is strong and light and magnesium chloride as a “Green” alternative for salting in winter, as well as in the body, Mg is needed for more than 300 biochemical reactions!

Seeing the light and feeling the delight of the essential element magnesium, the students thanked Team Mg for their illuminating MLP project.

Iron

October 6, 2011 in Elements

Magnetic moments materialized as the 4th grade students studied iron in Ms Reavell’s class at École FACE School on Friday the 3rd of April, 2009, thanks to MLP Team Iron (Fe), Livienne César (Education student and Bachelor of Art, UQAM ’06) and Sixian Lin (B.Sc. student U Montréal).    Iron is another “essential element” for plant and animal growth, one with the power of becoming magnetic. After refreshing our memory of when we studied hemoglobin and rust dyeing way back in 3rd grade, we were reminded of the biological need for iron which serves in hemoglobin as a transporter, like a school bus, to carry oxygen from the lungs to the body and carbon dioxide from the body to the lungs.  The students then examined a variety of magnets.  Sixian showed that magnetism could be transferred from a magnet to an iron nail, which was later used to make a compass pointing to the Earth’s magnetic north pole. The students made iron filings dance when moving a magnet under the table.  They learned that electricity could change iron into a magnet and explored the workings of an electromagnet.  Magnetizing all the iron around them with magnets and thinking about what is magnetic, the students assembled their own refrigerator magnets guided by Livienne and painted with iron oxide paint pigments that were brought back by MLP Team Mars when they visited the “red planet”, which has soil that is rich in iron oxide.

Grateful for their electromagnetic MLP experience, the students thanked Team Fe for showing us the powers of iron and magnetism.

For more information about iron see: http://mysite.du.edu/~jcalvert/phys/iron.htm

For lesson plan ideas about the role of iron in the human body : http://moleculesoflife.ca/2012/06/teach-about-hemoglobin/