In the September issue we asked readers to find our “egg-on-the-face” cover mistake, a cheeky “W”, and then share a story of a mistake made while teaching. We had some great replies. Thanks to all those who shared their stories with us. Graham Satterthwaite from Sir Robert Borden High School, Nepean Ontario was randomly drawn from the entries and has won a signed copy of the book, The Drunkard's Walk: How Randomness Rules Our Lives by author Leonard Mlodinow. Here is a selection of some of the entries.
Selection of entries
Marjorie Sutherland (18ish year subscriber)
Woodland Christian High School, Breslau ON
Bravo for making this mistake into an opportunity for teachers to share! In true science style — you've demonstrated that hidden in every error is a pearl of creative problem-solving.
Bayview Secondary School, Richmond Hill ON
My class was burning magnesium strips in crucibles to determine the empirical formula of magnesium oxide. This lab has a very high success rate, although we sometimes have students that, for whatever reason, cannot seem to get their magnesium to ignite. In this particular class, one group was having the most terrible time — again and again their magnesium was turning coal black and shrivelling up to nearly nothing. After checking their Bunsen burner, crucible and asking them several times if they had thoroughly cleaned their magnesium with steel wool, I stepped in to watch their process from beginning to end, as I had never seen the results they were observing in 14 years of performing the same experiment.
Turns out that instead of taking the provided pieces of magnesium, they had found leftover spark timer tape that some physics students had carelessly left on the lab benches from a previous experiment. Though the surface was a bit metallic and shiny, this group was burning strips of paper instead of magnesium in their crucible.
Lesson learned: even the most simple details can be overlooked.
Edwin Chong (retired)
This happened in the seventies, pre-semestering, pre-word processing, pre-Scantron and dittos ruled!!! We had six sections of grade 12 Chemistry (first Chem course back then) taught by three teachers. One teacher composed the final exam and gave it to the others for their input. After everyone was satisfied it then went to the office to be typed. Each teacher then proofread the typed copy, made corrections and sent it back to the office. The final copy was then proofread and approved for printing by all the teachers involved and the department head. The office printed around 180 copies (using some type of Gestetner process as I recall), which were then stored in the school’s vault!
On the morning of the exam, I picked up all the exams, took one look, and was horrified. The multiple choice section had a little bracket to the far right of the question where the student would write the letter of the answer. One of the teachers working through the exam must have written in the answers lightly in pencil. The typist typed them in and we all missed this completely! This was about an hour before the exam; thank goodness I am an early bird.
Here was my solution. I immediately got hold of the paper cutter and started removing the right side of the paper — every single one. We instructed the students to simply circle the best response. I do not recall any student commenting on the skinny paper since it was about 7 x 14 instead of the standard 8.5 x 14! So I completely understand how the extra W on the cover of the beautiful Sept 2016 Chem 13 News could have been missed.
Back when I was a beginner teacher (around 1967), I wanted to demonstrate to the 10th Grade that one could crystallize sulphur from a warm solution in toluene —now banned in most schools all over the world. I took a large — 30 mL at least — test-tube, placed sulphur in it and added about 10 mL of toluene. My plan was to dissolve the sulphur by heating, then filter the warm solution into another tube, where crystallization would take place.
I find it hard to admit, but instead of warming it in a water bath, I heated it on an open flame! I didn't take into account how easily toluene boils (b.p. 111 °C): I not only boiled over but caught fire as it spilt over my hands, my books, the desk — very impressive! I put it out quickly by smothering the fire with the other hand — it wasn't so hot.
At the end of the school year I asked my students which, of the many demonstrations and experiments that they had either done or watched, they enjoyed the most. One boy answered: "The class when you set fire to yourself!" I think the lessons drawn from this mistake are pretty obvious!
Arrupe Jesuit High School, Denver CO
My egg-on-the-face story happened last year, my 18th year of teaching high-school science. It's amazing how I keep making mistakes! I thought I'd be hip to teenage lingo and use the phrase "Netflix and chill" to describe how I like to go home and relax to a Netflix series.
Once the laughter died down, and I asked the students what they were laughing about, I turned beet red to find that "Netflix and chill" isn't at all what I thought but rather, well, I think you might want to google it. It's too embarrassing to even type.
To make matters worse, I had a student teacher in the classroom!
Lyle Sadavoy (retired)
When it came to school competitions, I had always been very competitive. Every year as we approached Halloween, our Student Council would run a pumpkin carving contest. My homeroom would carve a pumpkin and then I would spice it up with various chemical reactions.
Typically, I would use aquarium pumps to mix hydrogen chloride and ammonia to make the pumpkin "smoke" through every orifice, and I would have a flask containing potassium chlorate and sugar nestled inside the pumpkin. When the judges arrived at our class I would invite them in and drop some concentrated sulfuric acid into the flask to set off the reaction. With the ammonium chloride smoke and subsequent flames and dense smoke, invariably our class would win the pizza party.
One year I had a grade 12 home room, and I could not afford the in-class time for the judges. So I set the pumpkin on a stool outside the classroom and went on with the lesson while waiting for the judges to arrive. In due time, the judges came by our door and I turned on the pumps for the smoke and set off the flask. It was a joy to behold! Until seconds later the fire alarm went off.
In the classroom the smoke had been fine but in the low ceilinged hallway, and the rush of dense smoke, the fire alarm was overcome. Naturally, the school had to evacuate on a cold and windy October day. Since it was the last school day before Halloween, we were of course in costume. I was dressed in a lovely green silk sari, replete with necklaces and bracelets.
Since it was not a drill and there was no opportunity to call off the alarm, we had to wait until the fire trucks arrived to check out the school. Of course there was no fire anywhere and the search took a long time. Finally I was asked to speak to the fire chief to explain the cause of the alarm and allow us back into the school.
Fortunately, there were no photos taken of me, dressed in a sari, standing by the fire truck explaining how the fire alarm tripped. It was not my finest moment! However, it was not the last time I inadvertently set off a fire alarm! But that is a story for another time. Oh yes, we did win the pumpkin carving contest.
Sir Robert Borden High School, Nepean ON
My embarrassing story: many years ago when we had to teach weather to the grade 10s — so thankful they took that out of the curriculum — I was up late one night doing a work sheet. Perhaps I had something else on my mind because instead of typing in "albedo", I typed in "libido". Of course spell check didn't pick up on it. Got to school the next morning, printed off copies for myself and colleagues and was on my way down to the copier to make class sets when, thankfully, one of my more observant colleagues came rushing after me to point out my mistake. Not sure if there is a lesson in this, perhaps just indicative of my stupidity.
University of Toronto, Toronto ON
This fall I did a "get to know a professor" session with a group of 50 first-year chemistry undergrads. I started describing how new lab experiments are designed and implemented, and mentioned that it is fun for students to make compounds that have "real-world relevance". Then I went on to say that our third-year students used to make a drug called modafinil, which will allegedly keep a person awake for 30 hours — you can imagine students were very interested in this! I told them that we stopped running the experiment because the starting material smelled like dope.
That's when a student in the front row asked "how do you actually know that, Professor Dicks"? I had to say "allegedly" again!
Andy Cherkas, retired
Yes indeed I made errors teaching. The most common error was with exam questions in which a chemical formula was somehow incorrect and did not get changed after proofreading, such as HSO4 for sulfuric acid. How these errors were handled was a bonus mark to the first student who caught the error and an extra bonus mark for correcting the error