activity

Chemical Methods for Developing Latent Fingerprints

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.

Sink or Swim: The Cartesian Diver

In this Activity, students assemble a Cartesian diver and observe the effects of changing the pressure and temperature. An optional extension challenges students to cause the diver to hit the bottom in one minute by connecting the diver bottle to a second bottle in which baking soda and vinegar are reacted.

Acid-Base Reactions with Carbon Dioxide

In this Activity, students investigate two acid-base reactions. In the first reaction, an aqueous solution of powdered laundry detergent is neutralized with the acid formed by the dissolution of exhaled carbon dioxide. This uses the spice turmeric as an indicator. In the second reaction, vinegar and baking soda produce carbon dioxide gas.

A Refrigerator Magnet Analog of Scanning-Probe Microscopy

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.

Soup or Salad? Investigating the Action of Enzymes in Fruit on Gelatin

In this Activity, students observe gelatin samples treated with substances that may or may not have an enzymatic effect on the protein in the gelatin. Substances used are fresh pineapple, canned pineapple, fresh pineapple that has been frozen and microwaved, and meat tenderizer.

Burning to Learn: An Introduction to Flame Retardants

In this Activity, students test common household substances to see how they change the way paper burns. Strips of filter paper are soaked in saturated solutions, dried, and briefly held in a flame. The Activity demonstrates the effectiveness of flame retardants. It could be used when discussing combustion reactions or during a unit on practical or everyday chemistry.

Acid Raindrops Keep Fallin' in My Lake

In this Activity, students simulate acid rain falling on lakes by adding vinegar to bowls of water. Several of the bowls contain solids such as crushed, low-dust chalk, sand, and lime. Students determine whether the solids affect the acidity of each solution over two days by periodically removing samples of each solution for testing with red cabbage indicator.

Anthocyanins: A Colorful Class of Compounds

In this Activity, students extract anthocyanins from flower petals and other plant matter. They observe what happens when vinegar or ammonia are added to the extracts. This Activity could be used as an introduction to the study of plant pigments and the idea that specific substances are responsible for the colors of objects.

Just Breathe: The Oxygen Content of Air

In this Activity, students determine the concentration (percent volume) of oxygen in air. They place small quantities of fine steel wool into a test tube that is then inverted in a beaker of water. Oxygen in the trapped air reacts with the iron to form rust. The Activity ties in well with atmospheric chemistry.