Each year we do an activity that involves Archimedes principle. You might wonder...why do this in chemistry? Leading up to the activity, students do a series of labs and activities that involve measuring, accuracy, precision, significant numbers and density. The culminating guided inquiry activity takes place by which students take an object, find the volume in multiple fluids and find the mass in multiple fluids. An examination of class data starts to show that the volume of a solid does not change in fluids but the mass in air and the mass in different fluids are different.
Is it possible to use materials found in high school chemistry labs to extract and subsequently detect cocaine on dollar bills? Let me know what you think after reading this blog post!
This exercise is intended as an ice-breaker for a first or second class meeting. It also serves as an introduction to physical & chemical properties and application of the macro/micro/symbolic representations of chemical phenomena. Finally, it also provides a framework to mention many of the topics to be covered in a general chem first semester course.
I had a tough week. I had a front row seat in which I witnessed someone almost lose their life. I also almost accidently deleted both of my class websites just days before the kids walk in as we are starting a one to one lap top program. Here is the amazing part to all this...I get something that we all get as teachers every year...a second chance.
In Chemical Mystery #7, a can of Coca-Cola was observed to sink in one container of water and yet float in another! This trick made use of the fact that the density of water changes with temperature.
Q: Does an unopened can of soda pop float or sink in water?
A: It depends!
See if you can figure out what is happening in this twist on the classic floating-and-sinking soda can experiment.
Inspired by Tom Kuntzleman*, I started using mysteries in my chemistry curriculum this past year. The first mystery I shared with my students was burning water. While my magician skills aren't perfect, I was able to get the students asking questions and proposing hypotheses. For my IB students, it really allowed me to delve into a number of topics (e.g. combustion, intermolecular forces, polarity, density). And thus an idea was born: Using one mystery per topic. In this blog post I'll discuss my beginning effort to find or develop a mystery for each topic within the IB Chemistry curriculum.
Solution to Chemical Mystery #6 is presented. Also, concepts related to the chemical can crush demo are briefly discussed.
Can you figure out how this experiment works?
Flinn Scientific has a great elearning video series. Many of the videos have master teachers demonstrating some great labs and techniques that they do in the classroom.