In order for the teaching of chemistry to contribute to the development of reflective and inquiring citizens, it is necessary for students to understand the relationship between their daily lives and the concepts of chemistry. This work aimed to evaluate how contextualized activities developed by a project with high school students of a public school in the state of Goiás helped to develop the significant learning of chemical concepts related to the theme garbage and recycling and promote critical and reflective thinking with respect to the social, economic and attitudinal aspects of the theme. The study employed a qualitative research methodology. The research tools consisted of interviews and semi-structured opines applied before and after the development of the proposed activities. The results indicated that contextualization is an important resource and that it may contribute to the formation of students, enabling them to make coherent decisions in light of problems faced by present day society.