EXPERIMENTATION AND SURFACE TENSION: BUILDING KNOWLEDGE THROUGH SCHOOL-BASED SCIENTIFIC INQUIRY

Abstract

Student demotivation in relation to the Exact Sciences has been a recurring challenge in the Brazilian educational scenario, especially because of the difficulty in relating theoretical content to everyday reality. Investigative experimentation has emerged as an effective strategy for reversing this situation, promoting meaningful learning by bringing theory and practice closer together. The aim of this work was to investigate the phenomenon of the surface tension of water through a practical activity, relating it to intermolecular interactions and the effects of different substances such as table salt and detergent. The proposal was carried out with 1st year high school students at a state school in Rio Grande do Sul, and consisted of challenging the students to estimate and test the number of drops that would fit on a coin, using different solutions. The results showed that salt increased surface tension by intensifying the cohesive forces between the water molecules, while detergent, acting as a surfactant, reduced these interactions, making it easier to break the liquid film. The analysis and discussion of the data by the students themselves encouraged the development of critical thinking, scientific argumentation and understanding of the concepts involved. The conclusion is that the investigative approach, by combining chemical content with experimental experience, boosts student interest and engagement, reaffirming the role of experimentation in chemistry teaching as a tool for actively constructing knowledge.