Nature of Scientific Knowledge

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.

Water Filtration

In this Activity, students make a water filtration column using a 2-liter plastic beverage bottle that contains layers of gravel, sand, and activated charcoal. They prepare a contaminated sample of water and examine the filtration ability of the column. This environmental chemistry Activity can be used to complement a celebration of Earth Day.

Millikan: Good to the Last (Oil) Drop

In this Activity, students simulate Millikan’s oil drop experiment using drop-shaped magnets and steel BBs. Students determine the mass of a single BB analogous to the way Millikan determined the charge of a single electron.

Whatever Floats (or Sinks) Your Can

In this Activity, students test whether cans of carbonated beverages sink or float in water and then determine whether caffeine content, soda color, or sugar content in the carbonated sodas is responsible for the buoyancy of the sealed cans. This Activity can be used as an introduction to density in a middle school physical science course, or a high school chemistry or physics course.

Cool! Rates of Heating and Cooling

In this Activity, students measure the rate of warming for a chilled thermometer bulb held in room temperature air, for a chilled bulb held between two fingers, and for a few milliliters of ice-cold water. Students discover that the warming process is not linear. This Activity emphasizes the importance of measuring temperature change and its relevance to other experiments.

How Does Your Laundry Glow?

In this Activity, students examine the effect of pH on the intensity and color of the emission of fluorescent dyes in liquid laundry detergent. They perform two titrations using vinegar to estimate the pH at which the fluorescence properties change. In the second titration, sodium bicarbonate is added to buffer the detergent solution.

Fluorescent Fun: Using a Homemade Fluorometer

In this Activity, students investigate the fluorescence of highlighter marker ink and the principles employed in studying fluorescent molecules using a homemade fluorometer and different colored filters.

Testing for Iodide in Table Salt

In this Activity, students use supermarket chemicals to test samples of table salt for the presence of iodine, an essential micronutrient added as iodide ion. The presence of iodide in the salt is made apparent by the appearance of a blue color.

Hold the Heat: Global Warming and Calorimetry

In this Activity, students perform quantitative calorimetric measurements on samples of ice/water heated by incandescent light bulbs and/or convection with room-temperature surroundings. They measure and graph temperature as a function of time.

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.