HS-PS3-2: Motion of Particles and Energy of Position

Solubility and Models

First, I had my students examine the conductivity of a puddle of water the size of a nickel. They checked for conductivity. Then they took a very small amount of sodium carbonate and a fresh puddle of water and pushed in a few crystals from the side.  You can still see the crystals in the water but it tested positive for conductivity. They had to explain this. They did the same with a fresh puddle of water and a few crystals of copper (II) sulfate. Again, it tested positive for conductivity but they could still see the blue crystal. Finally, they started again with another fresh puddle of water, pushed a few crystals of sodium carbonate on one side and on the opposite side they pushed in a few crystals of copper (II) sulfate.  After waiting five minutes, a solid dull blue precipitate formed in the middle.  Also, the drop tested positive for conductivity. 

Building Molar Mass

An advantage to teaching on the trimester schedule allows me the opportunity to teach the same course again roughly twelve weeks later. So after grading my 2nd trimester students’ Chemistry B final exams, I was able to evaluate certain topics that caused my students problems, reflect on my teaching, and then determine how I was going to better prepare my students in the 3rd trimester chemistry B class.

Representing the Macroscopic, Particulate, Symbolic, & Real World Representations of Chemical Reactions.

 Last year while attending the Biennial Conference on Chemical Education at GVSU I had the opportunity to hear a talk that showed a video of a chemical demonstration showing the burning of magnesium metal.  We have all seen many of these videos (thank you YouTube) and probably have performed this demo for our own students many times.  During the video it may have been represented with a chemical equation followed by the students being asked to balance the equation or maybe even predict the products.  Although the use of video including the showing of the equation nicely represents the macroscopic and symbolic representation, what was so unique about this particular video is that it also included the particulate representation embedded on top of the video of the demo.  This was the first time I had seen the particulate level representation done like that and so I was intrigued in wanting to find more of these representations.  

Energizer Lab - A Target Inquiry Activity

This lab was written as part of the Target Inquiry program at Grand Valley State University in Michigan. Students build an electrochemical cell, learn about the symbolic equations used in electrochemistry and manipulate a model representing the particulate level of what is happening during the electrochemical process.