high school chemistry
In an earlier post, I discuss some of my unit planning that (I hope!) further breaks down a few of these misconceptions - my students are not teaching themselves on google. They are weaving back and forth between learning content and the larger reason for learning the content.
However, every single one of these comments above are valid. It is really difficult work to ultimately balance individual accountability and group accountability. Every student needs to master basic stoichiometry before they leave my general chemistry course.
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.
Are kids learning? Given the time it takes to implement and grade the activity, do I get a lot of "educational moments" out of it? Does it fit into the culture of the classroom? Is there a great deal of "conceptually rich" material in the activity that students can build on? I believe that two activities I tried this week fit the bill.
You can perform an orange to black chemistry demonstration using materials commonly found in stores. The reaction appears to be similar to the Old Nassau reaction, but uses greener reagents. This is a great demonstration to do around Halloween time.
Common drain cleaners consist of water, sodium hypochlorite (bleach) and sodium hydroxide (base) and/or potassium hydroxide (base). Bases are caustic (caustic loosely means to gnaw or eat away at) and can cause corrosion in metal pipes. Wouldn’t you know, our house has PVC piping through the fixtures that dump into a 45 year old cast iron pipe. The cast iron pipe is old and currently shows signs of surface rust and corrosion to the point where the pipe appears to be leaking then sealing itself in several spots. Not to mention the interior of the cast iron pipe may not be completely open, thus, not permitting a fast flow in drainage. Good news: a home warranty is being taken advantage of to hopefully replace the cast iron pipe with a PVC pipe.
A few years ago, we launched a weather balloon during our summer science camp. The balloon reached an altitude of 30 km (100,000 ft)! Among other things, this project ended up being a great way to teach campers about the gas laws and how atmospheric pressure decreases with altitude.
Instead of focusing on an instructional label, why don’t we focus on what we are trying to accomplish with our students? Our classrooms should be a platform for students to actively explain science practices using evidence and no matter how you define your instruction, we cannot deny our students this opportunity. With the implementation of the Next Generation Science Standards, our students will be assessed based on performance expectations that not only link disciplinary knowledge, but scientific practice, and crosscutting concepts as well. “These performance expectations guide the development of assessments: when a standard encompasses all three strands, then so must the assessment. It will no longer be possible to meet a standard solely by recall of factual knowledge.” (Cooper, 2013).
Every few years there seems to be some type of new technique that is developed that has hope and promise as an educational innovation. Currently, "flipping" the classroom has been getting much attention. Surely, the research will come concerning this technique. What you are going to read here is the brief story of an attempt by one teacher to "flip" things. You will get the good, the bad and the ugly.
This is my first year of using Modeling Instruction in my chemistry classes. During a fit of productivity, I created some bell ringers for unit one, which is partly about conservation of mass. I hope you will find them useful. Comments are welcome. I would love to see what others might be using.
You can access the bell ringers below. They are part of the "student document".
Approximately 5 minutes per class period.