HELPING STUDENTS TO MAKE INFERENCES ABOUT THE ATOMIC REALM BY DELAYING THE PRESENTATION OF ATOMIC STRUCTURE

Abstract

The presentation in many introductory college chemistry courses jumps around in an unsystematic fashion among the domains of macroscopic observation, sub-microscopic particles, and symbolic representation, making it difficult for students to construct a coherent picture of the discipline. Such presentations usually pay little attention to the intellectual struggle that led to fundamental knowledge in chemistry. Topics like atomic and molecular structure are often introduced early in the course, even though they are far removed from direct experience, and historically were elucidated relatively late in the history of chemistry. This paper describes a freshman chemistry curriculum, in which the topic of atomic structure is delayed until the second semester. Concept development is linked to the observable behavior of matter, while the sub-microscopic and symbolic realms are introduced by engaging students in some of the detective work that established the relative atomic masses of the elements and formulas of simple compounds. In this way, students have an opportunity to become familiar with the relationships among facts, definitions, hypotheses, deductions, and predictions, which are central to the enterprise of science. A brief review of literature dealing with relevant history and educational research is included. [Chem. Educ. Res. Pract. Eur.: 2001, 2, 183-202]