Periodicity Trees in a Secondary Criterion of Periodic Classification: Its Implications for Science Teaching and Communication

Abstract

In this work, I will present a proposal for introductory courses in chemistry. After the topics of atomic structure, chemical periodicity and chemical bonding, this proposal addresses the study of the periodic system based on triads, which has closed structures called periodicity trees as a secondary periodic criterion. This table was designed from a classical chemical perspective, with the purpose of integrating traditional topics and of supplying a conceptual basis for new ones, and, mainly, to privilege the chemical over the physical approach in the process of teaching-learning chemistry in initial courses.