density

It looks as though I’ve discovered that density bottles can be used to explore differences between heterogeneous and homogeneous mixtures!

As I began to prepare my labs for this upcoming year, I decided to put a bit of a twist on a previous density of a block lab I had used in the past entitled the Measurement Challenge that is sold by Flinn Scientific.

This was my first week of classes. It is the beginning of the 30^th year that I have been a high school teacher and the 28^th straight year I have been in the same physical classroom. Shockingly, all of those in the same school (yes I meant it to sound that way).

Are you familiar with the dynamic density bottle experiment? This interesting experiment was invented by Lynn Higgins, and is sold by various science supply companies.^1,2 Two immiscible liquids (usually salt water and isopropyl alcohol) and two different types of plastic pieces are contained within a dynamic density bottle.

Like most chemistry teachers, one of the first things I go over in the beginning of the year is unit conversions. Students come into my class with all sorts of prior knowledge concerning unit conversions; some good, some bad and some downright ugly.

Chemical Mystery #7: Curious Cans Q: Does an unopened can of soda pop float or sink in water? A: It depends!

Each spring my Local Section of The American Chemical Society (ACS) hosts a rigorous two part exam as part of the selection process for the The International Chemistry Olympiad (IChO).

One day during class I presented the disappearing rainbow demonstration and explained the chemistry behind it. After doing so, I had a student ask me if a particular bartending trick called “rainbow shots” was done in a manner similar to the way the disappearing rainbow demonstration is performed.