2-PS1-4

Milk and Soap Experiment

Description:  Milk is made up of water, fat, and proteins. Each of these molecules have charges and are held together by intramolecular forces. When the dish soap is added to the plate it quickly disperses across the surface as it is attracted to the water molecules and the food coloring is pulled along. This could be used as an anchoring phenomenon on matter, materials, or intramolecular forces.

Web Resource:  Colors on the Mooooove - ACS

 
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Supercooled Water

Description:  Supercooling occurs when the temperature of a liquid is lowered below the freezing point without forming a solid. In the case of water it needs a seed crystal or a nucleation site to start forming ice. If the water has been filtered through reverse osmosis or chemical demineralization it can be safely cooled below the freezing point. Simply shaking the bottle forms solid ice.

Web Resource:  Supercooling - Wikpedia

 
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Sugar and Sulfuric Acid

Description:  When sulfuric acid is added to sugar it removes the water leaving elemental carbon. The water quickly turns to water vapor creating the pores in the black snake-like column. This dramatic phenomenon can be used to illustrate chemical reactions, thermal energy released during a reaction, and conservation of mass. Safety precautions should be taken whenever dealing with acids.

Web Resource:  Sulfuric Acid and Sugar Demonstration - Thought Co.

 

Reaction in a Bag

Description:  This video shows a chemical reaction of sodium bicarbonate (baking soda), calcium chloride (road salt), and an indicator phenol red. The chemicals react to form calcium carbonate, sodium chloride, and carbon dioxide gas. This changes the pH inside the bag resulting in a color change in the phenol red. As much air as possible should be removed from the bag as possible to show the production of the gas. This could be used as an example of chemical reaction that releases energy (exothermic). Since the bag is sealed it could be massed before and after to show the conservation of mass (atoms). This phenomenon was submitted by Brian Babulic.

Web Resources:  Reaction in a Bag - Flinn Scientific, American Chemical Society - Explanation

 

Reusable Heat Packs

Description:  This phenomenon uses a supersaturated solution of sodium acetate. Clicking the metal disc releases a small number of crystals of sodium acetate which act as nucleation sites for the crystallization of the sodium acetate into a hydrated salt. Energy is released from the crystal lattice. The heating pack can be placed in boiling water and the sodium acetate can be dissolved again. This phenomenon shows how bond energy can be released.  It also shows the importance of chemical engineering and could lead to a section where students design a device (or application) of their own.

Web Resource:  Chemical Heat Pack - Wikipedia, Snappy Heat - Amazon

 

Ice Cube Spikes

Description:  Ice cube spikes form when the exterior of the ice cube freezes first and the expanding water from the inside is forced out through a small hole or weak spot in the exterior. The phenomenon can be used to show the reversible change of freezing in elementary or the intermolecular forces between molecules in high school chemistry.

Web Resource: Spikes on Ice Cubes

 
 

Slime

Description:  Everyone loves slime...especially elementary students. This phenomenon is a great introduction into chemical reactions. The properties of the reactants can be compared to the properties of the products to show that a chemical reaction has occurred. In high school the chemistry of polymers and cross-linking can be explored through slime.

Web Resource:  The Science of Slime - American Chemical Society

 

Elephant Toothpaste

Description:  Elephant toothpaste is a dramatic chemistry demonstration that involves the decomposition of concentrated hydrogen peroxide (H2O2) into water and oxygen. Potassium iodide is used as a catalyst to speed up the reaction. Soap is added to trap the escaping oxygen gas and food coloring is often added to the experiment. This phenomenon can be using in elementary science classes to illustrate non-reversible reactions and can be studied in more detail in middle and high school.

Web Resource:  Elephant toothpaste - Wikipedia