Glowing Gelatin Dessert: An In-Class Spectroscopy Activity

Abstract

The vivid colors of visible spectroscopy are amenable to classroom activities where students can view a demonstration and make observations. Here we report an active learning in-class activity that combines both absorption and luminescence spectroscopy. The activity is based on an outreach demonstration involving glowing gelatin dessert. Students use absorbance and luminescence spectra to determine the optimal color of gelatin to prepare the brightest and most impactful demonstration. During the activity, students learn the difference between absorption and emission and the relationship between λ max and observed solution color and emission color, and they consider preparing a demonstration for outreach activities. Surveys and assessment demonstrated that students enjoyed the activity and that the activity reinforced these concepts and contributed to learning of these topics. Instructors may implement this activity with or without the demonstration, as a worksheet and photos are provided.