# activity

## Modeling Dynamic Equilibrium with Coins

This Activity explores factors that influence dynamic equilibrium, including how long it takes two populations to equilibrate, and the relative amounts of reactants and products present at equilibrium. Students first use concrete objects (coins), then progress to mathematical calculations of equilibrium without physically manipulating the objects.

## A Candle in the Wind

In this Activity, students investigate physical changes that occur in a candle to learn how a candle functions and how you can blow it out. This Activity is based on a series of lectures presented by Michael Faraday in the 1850s.

## Pondering Packing Peanut Polymers

In this Activity, students compare polystrene and cornstarch packing materials ("peanuts"). Both are made of polymers, but because of their composition, they behave very differently in various solvents. Students extrapolate how these differences in behavior relate to environmental effects, such as filling landfills with non-biodegradable materials.

## Soil Testing: Dig In!

In this Activity, students collect soil samples and characterize them by examining their physical appearance, water holding capacity, sedimentation, and pH. Based on their observations, they can see that different samples of something as universal as soil can be quite different from each other. This environmental chemistry Activity can be used to complement a celebration of Earth Day.

## Fun with Fingerprints: Cyanoacrylate Fuming

In this Activity, students develop fingerprints using the cyanoacrylate fuming method on different types of surfaces. They investigate the technique’s effectiveness and test the effects of changing the temperature and humidity of the fuming chamber.

## Bath Bubblers

In this Activity, students use citric acid and baking soda to make "bath bubblers" similar to those sold in bath and body stores. They investigate the fizzing reaction that occurs when the bubblers are added to both cold and hot water. Bringing this real world product into the classroom adds interest and can lead to creativity, while introducing both acid/base concepts and rates of reaction.

## Popcorn: What's in the Bag?

In this Activity, students investigate microwave popcorn, the process of microwave-promoted popping, and the materials involved: water, vegetable oils, starch, and special packaging materials. This Activity supports discussion of thermal and electromagnetic energy, phase changes, intermolecular forces, patterns of solubility, and the structure of fats, oils and starches.

## The Sweeter Side of Density

In this Activity, students determine the density of different sugar solutions (0-50%). They then dye the solutions and devise a method to combine the solutions to make a multi-colored, layered heterogeneous mixture. This Activity could be used in units dealing with measurement or density.

## Some Like It Hot, Some Like It Cold

In this Activity, students combine liquids in a calorimeter and use a thermometer to determine if the reaction mixture gets hot or cold. All of the chemicals (yeast, hydrogen peroxide, vinegar and baking soda) except ammonium nitrate, are available in supermarkets.

## Ions or Molecules? Polymer Gels Can Tell

In this Activity, students first prepare a gel using the superabsorbent polymer sodium polyacrylate (found in certain diapers) and water. The gel is split into piles and samples of different compounds are sprinkled on the piles. Students determine that ionic compounds break down the gel, while covalent compounds have no effect on the gel.