The objective of this work is to analyze the explanations of pre-service physics teachers, when they experience with different electrostatic phenomena included in a teaching and learning sequence (TLS). This TLS was designed for students to use the model of distribution and interaction between electric charges at first, for then promote that they explain certain more complex phenomena with the electric field model. The results show a significant improvement of the students' explanations throughout the TLS due to several factors, including the teacher's role.