Thursday, January 29, 2015

When Kids Cheat...

Cheating is such a frustrating part of my job.  I know that kids cheat on homework assignments and lab reports.  So I have to work to safeguard my assignments from mindless regurgitation of facts.  I need to create assignments with answers that cannot be googled.  I have to make up ways for students to demonstrate their knowledge that is different from what I did last year because most of my assessments are electronic and "out there" on student machines.  With my AP Chemistry class, I have to record all the past questions I've used to prevent reuse in less than four years.  And, shame on me for assigning the questions from the lab kits, those answers are all easily googled in seconds.  I have moved toward collaborative lab report writing because the most frequent cheating cases were from one lab partner copying another.  Now I have students write the report together, in class, so that they can develop their ideas as a team.  Working towards "cheat proof" assignments only gets me so far.  What really bothers me about the academic dishonesty problem is the emphasis on earning a grade rather than actual learning.

As a teacher I work very hard to create engaging learning experiences for kids.  My heart goes into labs and demonstrations to find many ways to help kids to learn difficult chemistry concepts.  But there's always that point where the fun stops and the kids have to demonstrate what they've learned.  Inevitably there's the question, "Is this on the test?"  I know that sounds so cliche, but kids ask it all the time!   To say my kids are grade motivated is an understatement.  Kids in my class will ask to revise their work, do test corrections, or re-work homework problems.  I should be thrilled by this extra effort, but in the end it's just another attempt to earn a grade, not learn the chemistry.  Do kids actually care about learning?  The pressure to get an A on their transcript is very real and in the forefront of my students minds.  Somewhere along the way they traded in their excitement for learning for stress about GPA.   I wish that I could infuse them with some of the joy that comes from learning something new.  Wouldn't it be great if I could tap into the curiosity and excitement that you see in an elementary school classroom, the same energy these high schoolers had only a few years ago.

When kids cheat on their work, I am reminded that my job as a teacher is a complicated balancing act.  I want to foster exciting learning opportunities while upholding a standard of mastery of the chemistry.  All of this is happening in short segments of time that, for my students, is crammed between five other demanding classes with teachers just as eager to inspire and motivate them to master their subjects.  Place that in the context of a boarding school experience that includes sports, dorm life, and social events, and it's no wonder kids are looking for a quick way to get to the end of an assignment.  Drinking from the fire hose, you might say.  Throw in the competition for college admissions and you have the perfect storm of stressed out teenagers.  In the face of what seems like an impossible task, I am trying to keep my focus on learning.  I want to challenge my students to learn; and if they enjoy the process, great, and if they walk away thinking "Chemistry is pretty cool", then I've succeeded. 

Wednesday, January 14, 2015

Blow the Lid Off of Magnesium Oxide Lab

Magnesium reacting with oxygen in a red-hot crucible
Photo by Julia Paneyko
Every chemistry student makes magnesium oxide in the lab in their introductory course.  My students do it twice in my lab program:  once in the study of chemical reactions (types of chemical reactions lab) and then again in the mole unit.  High school chemistry students around the world are determining the chemical formula of magnesium oxide in this classic experiment.  I use this experiment as my first "mole concept application".

The procedure is very simple:  heat magnesium in a crucible until it is fully reacted with oxygen.  Use the mass data of the magnesium before reaction and product after reaction to calculate the mole ratio of Mg and O in the compound.  This mole ratio is the experimental chemical formula of magnesium oxide.  My "go to" procedure for this lab is found in ChemTopic Labs Volume 7:  Molar Relationships & Stoichiometry by Flinn.  In Flinn's version of the lab, there are detailed instructions to heat the magnesium with the lid on, then open the lid every three minutes, and then heat it some more with the lid at a tilt.  All of this manipulation of the crucible lid invariably results in at least one dropped and broken lid each lab period.  And, the results of the lab are usually not that great, with many groups getting ratios other than the expected 1:1.

My students are heating their crucibles with lids off.
This year I decided to try the lab with no lid on the crucible during the heating process.  It seems only obvious to let the maximum amount of air into the reaction by just leaving it open for the whole reaction.  I was a little nervous that burning magnesium might pop out of the crucible, but that didn't happen all day.  The hardest part of the experiment was adjusting the bunsen burner so that it would get hot enough to start the reaction.  Most of the reactions burned at a steady rate, without a big flare up of bright light.  Once the reactions were completed without any safety issues, my students crunched the numbers.

Here's where the big payoff was obvious.  The lab results were much better this year, with most groups getting the expected 1:1 ratio without the need for sad stories about experimental errors in the conclusion.  Taking the lid off resulted in better results, more interesting observations during the reaction, and better results for the chemical formula for magnesium oxide.

Wednesday, January 7, 2015

Mole Art

My new mole is making friends in class.
As a new teacher I thought that I would never be like my quirky science teacher colleagues, but after nearly twenty years of teaching chemistry, I have developed a weakness for “Mole Art”.  I love the element of fun that mole art brings to my teaching environment.  My students get a little glimpse into my soul when I bring in a new hand-made mole to decorate my classroom. 

Milli Mole
It started about seven years ago when I discovered a stuffed mole pattern in ChemTopic Labs Volume 7:  Molar Relationships & Stoichiometry by Flinn.  The pattern is very easy and quick to make.  I made three immediately: a custom designed mole for every chemistry teacher at my school.  The department chair got a mole in school colors with a “P” on the side for Pomfret.  My other colleague got a mole made out of her college school colors, adorned with flowers so everyone could tell it was a “she-mole”.  I named my first mole Milli, and I even gave her a rabbit fur hat (made out of fur that fell off of our rabbit pelt when I was demonstrating the polarity of water).  I manage to find reasons to have my mole in class throughout the year. I bring her out on the first day that I introduce the mole, and then again when my students learn molarity. 
The image of a one molar solution will always stay fresh in their minds when then think of Milli sitting in a one-liter beaker.  But wait, I can double the concentration by adding one of her mole friends to the beaker.  The site of the two moles crammed into a one-liter beaker always makes me laugh out loud.  My students quickly realize that not only do I like to make things by hand, but I also enjoy bad jokes! 
A one molar solution!

My new Mole Doorstop, the latest addition to the mole art collection.
My latest mole creation is a wonderful mole doorstop, which was inspired by a great book called Faux Taxidermy Knits by Louise Walker.  This fun book is a must read for every knitter.  The mole doorstop was very fun to make; and it knit up in just one day!  When it is finished, the mole is emerging from a mound of dirt as if to say hello to everyone.  The base is filled with rocks to weigh it down so that it will function as a doorstop.  I made the new mole just in time for the start of the mole unit.  On the first day of the mole concept, I split my class into small groups to do the POGIL activity called “Relative Mass and the Mole”.  (POGIL Activities for High School Chemistry by Laura Trout)  One of my students came up to the front of the room and brought the mole back to his table for inspiration.  I saw him with his arm around the mole during class, as if he wanted to include the mole in the group discussion.  When the novelty wears off, I’ll put him to work as a doorstop, but for now he is located on the front table to greet my students when they come to class for more mole calculations. 

A two molar solution!

In addition to the mole doorstop and the fuzzy mole friends I have made, I also have a handsome mole mobile hanging in the room.  I call it the molebile.  Two years ago our Head of School charged us to “make your space your own” at the start of the school year.  He said, “Give your classroom some personality and make it a fun learning environment”.  I knew exactly what I had to do:  make more moles.  For this mole art piece, I used the same stuffed mole pattern from Flinn to make a set of moles in bright colors. 
The original "molebile".
I have bins of fabric scraps for just this kind of spontaneous project.  I found some antiquated glassware in our stock room to serve as the perfect vehicle for the bright moles.  I always enjoy the moment when my students finally understand the molebile, usually a few days (or weeks) after I introduce the concept. 
The second "Molebile" I made for my friend in the lab upstairs.

Mole art is just one of the ways that I try to make chemistry a fun and memorable experience for my students.  I never underestimate the value of a good sense of humor in the science classroom.

The class mole, Bernard Martin, is giving some inspiration during the mole test.