From inert object to chemical substance: Students' initial conceptions and conceptual development during an introductory experimental chemistry sequence

Abstract

Children develop common conceptions about substances as inert objects as a result of their everyday life experiences. In order to promote conceptual development, 168 Greek students (aged 13-14) were involved in a new sociocultural situation, a specially designed introductory chemistry sequence. During the sequence, the students observed and expressed their ideas about 11 - unknown to them- substances, and 18 interactions between these substances, by answering a written questionnaire on various tasks. These tasks comprised description and differentiation of the initial substances, and prediction, description, and explanation of the interactions between them. Twelve of the 168 students were also interviewed. The analysis of the students' answers showed that conceptual development did occur during the sequence: the students moved from the "concrete substance" conceptual scheme toward the "unknown substance plus properties" scheme, and from the "inert mixture" idea to the "interaction" idea. Moreover, the students' initial reasoning- based on the "recognition" of substances - evolved toward a primitive "identification" process. Informed by these data, we formulate propositions regarding a chemical substances approach, in order to further improve students' conceptions during the teaching of chemistry. © 2000 John Wiley & Sons, Inc. Sci Ed 84:382-400, 2000.