I found a version of this demonstration online a couple of years ago. I admit, when I first tried it with my class it was mostly for a crowd pleaser to demonstrate the activity series of metals, but I then became very intrigued by the processes occurring. The original source only referenced the “single replacement reaction” between Mg(s) and AgNO3(aq). Therefore, when I saw a grayish product (silver) I was not surprised. However, I was surprised by the white flash and the production of a white product, which were reminiscent of the classic combustion of magnesium demonstration. This led to some research and my conclusions that follow. Read through to the end and you will find a video of the demo.
Looking over my student's papers, there may have been more misconceptions created because of the way I planned the curriculum. In all of the experiments students can see and observe that not all of the crystals or material dissolves yet the water starts to conduct. In their minds there is evidence that they believe either something DOES dissolve or it does NOT. Clearly, partial dissolving is initially too much to consider.
Have you ever wondered where the cloud comes from when dry ice is placed in water? If you think the answer is “atmospheric water vapor”, be sure to read this post because experimental evidence suggests that this explanation is wrong.
In teacher preparation, the Vygotsky based theory of formative assessment is integral because teachers and teacher educators who recognize their knowledge as knowledge in formation are better prepared to recognize the value of students’ knowledge. After all, most learners find it easier to build upon prior knowledge when learning material as opposed to having the material dissociated from prior experience and viewed as a completely new and isolated material.
“What we Call Misconceptions May be Necessary Stepping Stones Toward Making Sense of the World” is an article identifying how misconceptions can be turned into sense-making exercises and classroom conversations to help students come to meaningful, and eventually “correct” views of scientific concepts.
I have always been intrigued by the story of the Hindenburg, the iconic airship that caught fire on May 6, 1937. The accident killed 35 of the 100 passengers and crewmembers on board. As a chemistry teacher, I discuss this from a chemical standpoint and the fact that the airship was filled with hydrogen, a flammable gas, rather than helium, a non-flammable gas, as today’s modern airships are.
Tom Kuntzleman loves to share chemical mysteries and that inspired me to create a list of mysteries that are appropriate for the main topics covered in IB Chemistry. In this blog post I'd like to share some detail about how I modified the mystery of the burning water.
The September 2016 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: copper chemistry; safety; using brewing to teach chemistry; 3D-printed models; learning using games; open-ended approaches to teaching; innovative methods to teach biochemistry; polymer chemistry; organic synthesis labs; teaching physical chemistry; chemistry field trips.
Just this week I'm reviewing equilibrium with my IB Chemistry seniors after they finished some summer study on the topic. One of our classes was spent manipulating a classic equilibrium involving copper ions and a copper-chloride complex ion.
The first day of school for me has always been daunting for my new students (in AP chemistry, where I know the kids, it’s so much easier). I want my students to know the following: -Who is this tiny person who looks like a teenager (that’d be ME, folks)? Where did she come from and why is she teaching us? -What does chemistry look like?