From Cathode Rays to Alpha Particles to Quantum of Action: A Rational Reconstruction of Structure of the Atom and Its Implications for Chemistry Textbooks

Research in science education has recognized the importance of the history and philosophy of science. Given this perspective, it is important to analyze chemistry textbooks, at the freshman college level, to determine the degree to which they deal with recent developments in the history and philosophy of science. This study has the following objectives: of a (a) elaboration framework, based on a rational reconstruction of developments that led to the formulation of atomic models by Thomson, Rutherford, and Bohr; of eight criteria based on the framework (b) formulation that could be useful in the evaluation of chemistry textbooks; and of the textbooks (c) evaluation based on the criteria. Twenty-three textbooks were evaluated on the eight criteria. Results obtained show that most textbooks emphasize experimental details based on observations, leading to the presentation of scientific progress as a rhetoric of conclusions, based on irrevocable truths. Such an understanding lacks the conceptualization of the heuristic principles that led the scientists to design and interpret their experiments. For example, in the case of J. J. Thomson’s work, besides the experimental details of cathode ray experiments (emphasized by most textbooks), the “heuristic principle” involved the testing of rival hypotheses, namely a determination of the mass-to-charge ratio would have helped to identify cathode ray particles as an ion or a universal charged particle. Most textbooks presented the experimental details, without the conceptualization that progress in science is based on competing frameworks of understanding that clash in the face of evidence. It is concluded that textbooks should emphasize not only the experimental details but also the “heuristic principles” required to “structure inquiry.” q 1998 John Wiley & Sons, Inc. Sci Ed 82:527–552, 1998.