In Chemical Mystery #10, plastic straws are observed to “magically” change color when waved in the air. Check out the explanation and the video.
I think this experiment provides a fantastic vehicle to involve students of all ages in small, hands-on and exploratory research projects. Like many others, my students and I have investigated various aspects of this interesting fountain.
After spending the start of the year using a modified version of the Modeling Instruction curriculum (density and physical properties, followed by gas laws, followed by energy and phase changes), we don’t actually start talking about what’s inside atoms until December. I love that by this point students are already familiar with some of the habits of mind needed to reason abstractly about atoms -- thinking proportionally, explaining macroscopic observations at the particle level -- and we are ready to layer on both more abstraction and the symbolic level. By January, we are ready to explore electron configurations.
I recently stumbled upon this article and it is a super handy resource for kinetics labs (and a nice review of Analytical courses from my college days).
The chemistry of the Sky Blue dye found in McCormick's Color From Nature food colors is explored. This is part one of a three-part series in which the chemistry of McCormick's Color From Nature food colors is presented.
The solution to Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice is presented. Why does liquid nitrogen launch the bucket so much higher than dry ice and water?
A 2L soda pop bottle is filled about one-third full with either liquid nitrogen or solid carbon dioxide (dry ice) and water. The bottle is sealed and a plastic bucket is placed on top. Do you think the liquid nitrogen or dry ice and water will make the bucket go higher? Can you explain the results using chemistry?
You probably know what happens when you place dry ice in water. Do you know what happens when dry ice is placed in acetone or glycerin? Read this and find out!
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.
Precisely timed series of interventions lead to the growth of complex, three-dimensional microscale structures.