1. Home
  2. Demonstrations

Demonstrations

Ramping Up the Disappearing Rainbow with the Assassin’s Water Bottle

Tom Kuntzleman | Tue, 09/16/2025 - 09:44

What happens when chemistry and illusion collide? In The Disappearing Rainbow, a simple acid–base demonstration transforms into a spellbinding performance. With a single pour, colorless liquids bloom into a vibrant rainbow—then vanish in an instant. Now, with the arrival of the “Assassin’s water bottle,” this classic demo gets a modern twist that makes the magic easier (and cleaner) than ever.

Not so Green Up Close: a Peek at a dyed Chicago River Sample

Dean Campbell | Sat, 05/17/2025 - 22:36

Light absorbance and fluorescence were studied for a sample of the Chicago River that had been dyed green for St. Patrick’s Day. The sample had weak green fluorescence, showing that the intense green appearance of the river was in part due to the long path length of light through the water. The ability of the green color to partition into 1-octanol was also explored.

Egg-lectrons and McLewis Structures

Dean Campbell | Fri, 02/28/2025 - 22:13

Egg cartons and beverage holders can be used as models of atoms, with their dimples representing orbitals. Each dimple can hold up to two objects such as milk jug caps, plastic eggs, and cup pieces to represent electrons in the orbitals. Partially overlapping the trays by stacking the dimples represents chemical bonding and produces molecular models resembling Lewis structures. The models can be easily made from materials that can be readily found grocery stores and fast-food restaurants.