This research was performed aiming to map out which teacher's actions can promote argumentation by students. Therefore, we considered the context of inquiry-based teaching and the importance of this didactic approach to promote Scientific Literacy. We characterized the inquiry-based teaching and explained what is the place occupied of argumentation in an educational environment based on their assumptions. Based on the literature review, we discussed what is argumentation and its relevance to building up understandings by students about scientific contents. In light of these conjectures, we have structured a category group called epistemic purposes to promote argumentation that, together with the scientific literacy indicators proposed by Sasseron (2008) and the types of questions asked by a teacher proposed by Machado (2012), allowed us to design an analytical tool to study classroom empirical situation. Our data source consisted of records arising from the implementation of an Inquiry-based Teaching Sequence that addressed the subject wave-particle duality of light.Analyzing the transcripts of the speeches of students and teachers concerning to the final two classes of this teaching sequence was possible to find different types of arguments built by students. We concluded, among other things, the importance of the role of the teacher to promote the development of argumentation situations, since our interpretation of the data indicated aspects, as, for example, the need for resumption information, the questioning of situations and exploration of different points of views to construct arguments and understanding by students about the object that was being investigated collectively.