Entre rupturas e contronvérsias

estudos da composição do núcleo atômico

Abstract

The concept of the structure of matter, particularly the study of atomic structure, is embedded within a comprehensive historical context, multiple aspects of which remain to be explored in science teaching. The evidence of empty spaces within the atom is regarded as a major epistemological rupture, characterized by the existence of a positively charged nucleus surrounded by electrons. This discovery is commonly attributed to Ernest Rutherford, in collaboration with Hans Geiger and Ernest Marsden; however, the composition of the nucleus was ultimately established through numerous debates and controversies. The exploration of these episodes might be employed to enhance the teaching of atomic structure, as the development of the nuclear model occurred over decades and highlights the provisional and non-linear nature of scientific progress. It is frequently observed that presentations of Rutherford’s atomic model incorporate the nucleus as being composed of protons and neutrons, thereby omitting contributions from Rutherford’s own research and those of other scientists. The present work consists of a documental analysis of original research by Rutherford, James Chadwick, and other prominent scientists involved in twentieth-century studies of the atomic nucleus, including investigations into the hypotheses and evidence that led to the discovery of the neutron. In this context, related concepts—such as atomic number, electronic distribution, and radioactivity—are also addressed in order to underscore the foundational basis upon which these studies were developed. Based on the analysis of these materials, relevant arguments can be selected for use in educational settings, thereby contributing to the teaching of atomic models and providing information derived from primary sources that may be utilized by teachers.