Using experiments in chemistry teaching by flipped classroom model to develop representation competency for 11th students

Experiments are a characteristic and visual aids in teaching chemistry and they are used for a variety of purposes. Experiments can be used to develop students' capacity to use knowledge and skills through situations and foregrounds. The article presents some the following contents: Manifestations of the representation competency; Proposal of using experiments in teaching according to the flipped classroom model to develop students' representation competency; Illustrative examples in two topics of stoichiometry, nitrogen - sulfur in Chemistry Curriculum 2018 and the process of pedagogical experimentation at Nguyen Trai High School (Binh Duong) and Vinh Loc High School (Ho Chi Minh City). From the processing results, the number of definition ranges is calculated and the effectiveness of the proposed measure.