CHEMICAL ETHICS AND ITS TEACHING TO CHEMISTRY STUDENTS. This paper aims at broadening the understanding of scientific ethics by addressing chemical ethics, which deals with the benefits, risks and uncertainties associated with or arising from chemical activities. Chemical ethics is a theme of the Philosophy of Chemistry and its discussion has been recommended in Chemical Education. The purpose of its teaching is to recognize and analyze ethical problems, as well as to evaluate the possible paths that can be followed to make better decisions. In this paper, the implementation of a didactic intervention based on a historical case and on a hypothetical case in an undergraduate course is described. The aim of the intervention was to promote the development of ethical reasoning, instead of prescribing a specific ethical path, solution, or behavior. The historical case allowed students to understand the risks and uncertainties associated with the use of chemical substances. The hypothetical case made it possible to make ethical decisions by dealing with a problem situation, in which the characters’ possible decisions and their consequences were analyzed. Results show that the different approaches enable complementary understandings, which favor the development of students’ ethical reasoning.

The aim of this paper was to analyze the historical approaches to the periodic table in general chemistry textbooks used in Brazilian universities in the twentieth century. Textbooks were qualitatively analyzed according to the following criteria: position of the discussion about the periodic table in the book; presence or absence of a specific chapter on the subject; presentation of attempts to classify chemical elements before Mendeleev; presentation of the construction process of the periodic table by Mendeleev; identification of problems in the original table; discussion of Mendeleev's predictions about unknown elements; organization of the periodic table; periodic properties presented and discussed; and the enunciation of the periodic law. The analysis revealed different approaches at specific periods of the twentieth century, from more descriptive approaches to emphasis on attempts to explain the periodic table in terms of atomic orbitals. These changes point to different ways of understanding chemistry during the period studied.