In chemistry education, understanding the structure and role of the Periodic Table has been linked to subsequent learning of key concepts such as the properties of chemical elements. However, the way teachers introduce the Periodic Table to high school students is mostly traditional, students learning to use it to predict properties of elements according to given rules (Ben-Zvi & Grenut, 2007). Such a way to proceed does not allow students to engage in authentic science activities. Thus our research pursues two main objectives. The first one is to conceive a learning sequence to engage students in activities where they have to propose their hypotheses and verify them against data. The second one is to study the condition of implementation of this learning sequence in high school chemistry course. The experimentation took place with 14 adult learners who followed a high school chemistry course in two successive periods of two hours each in an adult learning center. To study the implementation of the learning sequence, the main researcher held a research diary where he recorded his observations on the sequence of events. In it, he also wrote his reflections about the observed events and established links between his observations and the theoretical framework of the present research (Altrichter & Holly, 2005). Our results point out that the sequence engages students in developing the classifications as well as find arguments to test them as they discuss their ideas in small groups and later expose them during classroom discussion. We also discuss conditions of implementation, such as the importance of providing a way to register all the contributions of each team to help sharing and examining the various hypotheses. One key aspect concerns the ability of the teacher to find the proper balance between supporting students’ process of categorization while not interfering with it. As a conclusion, we discuss the advantages and the limits of the research and made suggestions for future research.
Constructing a Periodic Table: A Proposed Practice Activity for High School Chemistry Classes