The research has built a process of applying experimental methods in teaching Science composed of four stages. The design of appropriate teaching activities and the preparation of experimental means for teaching are important. Students participate in four types of activities including warm-up, inquiry, and discovery to find out how to perform experiments, report, and application activities. Students' activities start from asking questions or identifying problem situations related to the lesson requiring to be demonstrated using experimental methods. At the end of experimental activities, students must find examples of applying learned knowledge and explaining phenomena that occur in life from simple to advanced levels. The lesson plan "What properties does water have?" is designed according to the proposed teaching process. Through the experiment, the lesson plan was found to be effective in developing the natural science competencies for students according to the requirements of the 2018 Science Curriculum