The purpose of this study was to investigate how a chemistry teacher's questions influence the classroom discourse. It presents a fine-grained analysis of the rich variety of one teacher's questions and the roles they play in an upper secondary chemistry classroom. The study identifies six different functions for the teacher's questions: "Student Knowledge," "Request," "Monologic Discourse," "Clarification," "Relations" and "Interaction of Contexts." Overall, these questions create a safe and interactive learning environment. However, the questions are predominantly closed in form. As a result, the students become highly accomplished in recalling facts but have difficulties when higher order thinking is required. The findings suggest that an interactive classroom can be created by using many engaging teacher questions. The six different categories of questions promote the students' learning process as it gives them authority and entitles them to speak and learn.