WEATHERED M&M’S®: USING CANDIES TO DEMONSTRATE GEOLOGIC CONCEPTS IN LECTURE-BASED INTRODUCTORY EARTH SCIENCE COURSES

Students enrolling in introductory earth science courses at the St Louis Community College, Meramec, often have little or no science background. The course format is lecture-only with typically 25-30 students enrolled per section. Demonstrations to illustrate geologic concepts can be valuable teaching tools in such lecture-oriented earth science courses to facilitate student learning. Common brands of chocolate candies are good materials for classroom demonstrations because they are relatively inexpensive, easily obtainable, and familiar to the students. Additionally, learning is greatly enhanced when students are enjoying the taste of the lesson.

Concepts of physical and chemical weathering, erosion, transportation, deposition and lithification was illustrated using m&m’s® containing peanuts. Several pieces of candy were used as examples of unaltered igneous rock, which were then crushed up (physical weathering). The crushed pieces were dropped in a beaker containing water. The outer colored sugar coating dissolves rapidly in water, but the chocolate and the peanut pieces remain undissolved, illustrating the concept that different minerals respond differently to chemical weathering. The undissolved peanut and chocolate pieces were then used to illustrate transportation and deposition by water. The demonstration was followed by visual examples of differential weathering in real rock samples.

Student response to such demonstrations has been favorable. A large majority of the students taking this course during Spring 2002 semester stated that the classroom demonstrations were most helpful for understanding the materials covered in class.