analogies

Demo A Day IV

Dean Campbell uses demonstrations and props to illustrate concepts while teaching his collegiate Materials Chemistry course. Many of the examples described are also suitable for use in high school and collegiate General Chemistry courses. 

Unit Cells and Layer Sequences using Dimpled Packaging

Regularly dimpled trays such as those used in food packaging can be used to represent layers of atoms in solid structures. For example, the square array of dimples in transparent plastic mini quiche trays can be used to depict layers within cubic or tetragonal unit cells. Multiple solid structures and ways to represent those structures are described. 

Algae Connections to Chemistry Classrooms

This timely post is a perfect fit for the theme of Chemists Celebrate Earth Week 2023! Algae is a rich topic with many possible connections to the chemistry classroom. Algae needs to take in light, carbon dioxide, and various simple nutrients and, though it can sometimes get out of control, can produce oxygen, diatomaceous earth, and other products. It can even fluoresce pink! 

Surprising Shrinking Styrofoam Stick: Using the Gas Laws to Get a Square Peg into a Round Hole

Polystyrene foam sticks with a square or rectangular profile will not fit into a round target hole (e.g., the opening of a soda bottle) at room temperature. However, they do contract sufficiently in contact with liquid nitrogen to fit into the hole and produce a simple demonstration of Charles’s Law. Many other polymer foams do not shrink under these conditions, but still provide opportunities to discuss and explore their structure and chemistry.