activity

Turning on the Light

In this Activity, students investigate the luminescent properties of common items such as glow-in-the-dark stickers, wintergreen-flavored hard candies, and a chlorophyll solution made from spinach leaves. After making observations, they use a flowchart to categorize the luminescent items as fluorescent, phosphorescent, or triboluminescent.

The Nature of Hydrogen Bonding

In this Activity, students build models of polarized water molecules using K’nex toy components and adhesive Velcro. Students investigate hydrogen bonding by shaking the models in various ways. They observe the resulting interactions and relate their observations to physical states of water and the difference between strong bonds and weak attractions.

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.

Where There's Fire There's...

In this Activity, students compare the combustion of different substances such as a glowing wooden toothpick and lit birthday candle in air, oxygen, exhaled breath, and carbon dioxide environments. The oxygen and carbon dioxide are generated from supermarket chemicals. This Activity can be used to explore the chemistry of oxygen and combustion.

Investigating the Invisible: Attenuation of Radio Waves

In this Activity, students investigate properties of radiation using a handheld radio. Students compare the abilities of conductive and dielectric materials to attenuate or block, radio waves, and compare the attenuation of AM versus FM radio waves. The radio is placed inside different objects and students record which materials blocked or attenuated the waves.

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.

Diffusion of Water through a Differentially Permeable Membrane

In this Activity, students investigate the process of osmosis through a differentially-permeable membrane formed by the precipitation of copper(II) hexacyanoferrate(II). This Activity allows students to watch and investigate osmosis, which reinforces the concept of transport in living cells.

Mass Spectra

In this Activity, students solve puzzles that are analogous to finding the amino acid sequence of a peptide using mass spectrometry. Students identify words that have been broken into letters or groups of letters. In many textbooks instrumental analysis and various types of spectrometry are mentioned only in passing.

Colors in Liquid Crystals

In this Activity, students investigate the relationship between temperature and composition and the reflected and transmitted colors of a common nanoscale material, the cholesteric liquid crystal.

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.