Some metals and metal alloys undergo a transition to brittleness at cold temperature. This phenomenon likely contributed to the demise of the Titanic.
middle school science
Describing the number density of molecules involved in chemistry demonstrations while presenting those demonstrations can help to convey concepts such as the small size of molecules and how the distance between molecules can vary during change of physical state.
This Pumpkinator is a fantastic orange-to-blue-to-orange chemical reaction that will make a great addition to your Halloween-themed chemistry demonstrations.
Learn a bit about the chemical reactions that occur during a lightning strike, and how you can demonstrate these reactions in your classroom.
The importance of surface area can be illustrated by adding spherical solids at known sizes and temperature to other substances at different temperatures and then monitoring the rates of temperature changes of the system over time. Larger spheres (with less surface area per sample) exchanged heat with water more slowly than smaller spheres, and less thermally conductive glass spheres exchanged heat with water more slowly than iron spheres. Additional, more colorful demonstrations are described in which small glass spheres cool thermochromic plastic cups more quickly than larger glass spheres.
You can solve Chemical Mystery #20 if you know your chemistry...and your magic!
Why does the "Whoosh Bottle" experiment behave differently at different temperatures?
Can Alkaline Water Change the pH of your body? We use chemistry to put this claim to the test!
Flat, symmetrical molecules can be modeled by folding a sheet of paper, cutting patterns into the folded structure, and unfolding to produce the flat paper models. The finished models resemble paper snowflakes, but have a variety of rotational symmetries. Template patterns for several molecules are available for download in the Supporting Information.
Balloons that inflate using carbon dioxide produced from the reaction of citric acid and sodium hydrogen carbonate can be used to demonstrate a number of aspects of chemistry. Gas laws were used with the balloons to illustrate limiting reactants, molar mass of gases, and rockets. The endothermic reaction in the balloon was visualized with an infrared camera, and the Green Chemistry aspects of these balloons were considered.