The solution to Chemical Mystery #11, which involves the Leidenfrost Effect, is presented.
Fostering Creativity in Chemistry
The February 2017 online issue of the Journal of Chemical Education is now available to subscribers. Topics featured include: surface chemistry; chemical identity thinking; conceptual understanding; communicating science to the general public; activities and labs linking chemistry and art; history and chemistry; early access to research; technology as instructional support; synthesis laboratories; from the archives: bottle chemistry.
If you are like me and unable to attend BCCE 2014, there is still a way to be part of the action. Twitter! Even if you don't have a Twitter account, you can follow tweets from participants that are there "live tweeting" the action.
Fostering Engagement in Nanotechnology The Feburary 2014 issue of the Journal of Chemical Education is now available online to subscribers at http://pubs.acs.org/toc/jceda8/91/2. The February issue features articles on nanotechnology in the areas of public engagement, instrumentation, and laboratory experiments.
In this Activity, students marble paper with shaving cream and food color while exploring water, polarity, and hydrophilic and hydrophobic materials. Although the Activity is familiar, it contains a new twist—exploring how a colored shaving cream mixture behaves when a drop of water is added. This Activity can be used to introduce the concepts of polarity, soaps, and surfactants.
In this Activity, students investigate the magnetic interactions between a flexible-sheet refrigerator magnet and a probe tip cut from the same magnet to deduce the relative arrangement of the magnetic poles. These interactions are used as a macroscopic analog of scanning probe microscopies. The Activity could be used when atoms are introduced.
In this Activity, students investigate surface tension and surfactants. They count the number of drops they can place on a penny, attempt to make a "square" of drops, and create bubbles using differently-shaped wands. These mini-activities could be used to introduce surface tension and surface area when discussing properties of liquids and gases.
In this Activity, students collect fingerprints and use three different methods to develop them: fingerprint powder, ninhydrin solution, and silver nitrate solution. The Activity could be related to the solubility of polar and nonpolar molecules, precipitation reactions, and oxidation-reduction reactions.
In this Activity, students compare the behavior of Magic Sand and ordinary sand. They then predict and observe how new substances will interact with Magic Sand based on their observations. The Activity illustrates solubility principles, and the terms hydrophilic and hydrophobic. It also allows for extension into the practical realm, where students formulate real-world uses for Magic Sand.
In this Activity, students first create a standard bubble solution by mixing water with liquid dishwashing detergent. They then add different substances to samples of the detergent solution. The solutions are compared to see which produces the longest-lasting bubbles. The Activity is a fun way to introduce the concepts of surface tension, intermolecular forces, and the use of surfactants.