Linking macro and micro through element cycle: Desing research approach for introdutory chemistry course for 6-7 grades

Abstract

RussiaIntrochemist association, http://introchemist.org, Abstract To provide a solid understanding of chemistry at early stages of learning, any introductory course strives to link macro phenomena and their micro models in students' thinking through some practical work with substances and related modeling at micro level; however, the transition to elements and atoms does not get adequate consideration. Our goal is to design a teaching strategy that reveals the essence of the notion of chemical element at both levels of its representation. We assume that (1) connections between the macro and the micro can be realized if we allow students to plan the experiments, and (2) the necessary context in which the concept of chemical element really works is a problem of preparation of a certain substance from other chemicals. Upon these principles, we have developed a local instructional theory that has then been tested and revised during three long-term macro-cycles of our design research experiment in 6-7 grades. We build on the Guided Discovery Approach to teach students how to distinguish and interpret simple physical and chemical changes through the substance-based particle model. In our course, students compose and explore copper and iron cycles of transformations, model composition of particles of the substances involved, revise interpretations of the experiments, investigate displacement reactions, acids, bases, etc. without explicit references to the concept of atoms. Along this way, students realize and master the idea that elements are conserved in reactions and every element gives rise to a cycle. Atoms then emerge as units of elements. The principal advantage of this approach is the appearance of meaningful questions that the subsequent chemistry course will answer. Students acknowledge that models are revisable as needed by the experiments. Such an introduction makes the subject of chemistry much more meaningful for students and eliminates many obstacles to successful learning.

Logic Of Natural Sciences Through Historical Approach: Science For 5-6 Graders

“…Rather than being a mere opportunity to start the conversation, the historical materials are put in the center of our approach. (Vysotskaya, Khrebtova, & Rekhtman, 2015). Then, the same approach was applied to certain related scientific concepts, and a new version of our science course for 5graders is currently being tested (Vysotskaya, Khrebtova, Lobanova, Rekhtman, & Yanishevskaya, 2018).…”

“…At first, substances were described by their properties, and only when the modern chemistry was born, by their composition. So as a prerequisite, the students have to be familiar with the notion of "substance" and "chemical reaction" and master at least the two first items of the Basic Particle Model (Vysotskaya et al, 2015). For us, this was the main reason to focus on how these notions should to be introduced to younger kids, such that the subsequent learning of chemistry is given the proper basis.…”

“…on. Thus, the primary model that students build and develop further is the element cycle (Vysotskaya et al, 2015). Table 02 presents an overview of the course.…”

“…Each text describes an ancient technology using certain means of modeling that students can use to interpret it (see below). The technologies chosen serve various human needsfrom baking bread to smelting metal, see Table 03 ( Vysotskaya et al, 2015Vysotskaya et al, , 2018.…”

“…Students work with reagents that have no modern names or chemical formulas on the jars or flasks; they may be labeled either by their archaic names (the same that are used in the texts) or by the names that the students have given them previously; the latter is referred to as the parallel language (Vysotskaya et al, 2015).…”