Espectroscopia óptica: uma estratégia para uma aprendizagem significativa do modelo atômico no ensino médio

Abstract

This study analyzed the effectiveness of a didactic sequence (DS), grounded in Meaningful Learning theory, which utilizes a low-cost optical spectroscopy experiment to promote the reconstruction of subsumers and the acquisition of concepts related to atomic models and spectroscopy among 11th-grade high school students. The research adopted a qualitative approach with an exploratory and descriptive design. Data collection involved both preintervention discursive and post-intervention objective conceptual tests, as well as observation records. Data were analyzed qualitatively using the content analysis method applied to the students' responses. The DS was implemented with 25 students from a public school in Manaus, Amazonas. The results indicated that the pedagogical intervention was effective. In the pre-test, the majority of students did not demonstrate robust evidence of meaningful learning on the topics. However, after the DS was implemented, a significant learning gain was observed across all topics, as measured by Hake's normalized gain. Specifically, for Wien's Law, the normalized Hake gain was 0.79, which is considered high, indicating that students understood the relationship between wavelength and temperature. For the concepts of object color (absorption and reflection), the gain was 0.94, also classified as high, showing that students grasped the process of color formation. Regarding the atomic models, the gains were 0.47 for Dalton, 0.67 for Thomson, 0.46 for Rutherford, and 0.68 for Bohr. Although these gains are considered medium, they still represent a significant improvement compared to traditional methods. Finally, for spectral lines, the gain was 0.78, a high gain. The overall normalized gain of the DS was 0.67, which indicates that the teaching methodology employed fostered active student participation and the development of conceptual understanding, thus characterizing meaningful learning.