Development and application effect of gas concentration measure experiment for the improvement of elementary school teachers' concept on combustion

The purposes of this study were to develop the experiment for gas concentration measure during combustion of a candle and to investigate the application effect of the experiment. For this study, 15 elementary school teachers were selected by considering their gender, career, 6th grade science teaching experience, and 6th grade science teaching experience according to 2007 revised science curriculum. The experiment using MBL is designed to confirm gas concentrations visually during the combustion of a candle which burns in an acrylic container. The experiment method is as follows. 1) Make two sets of holes in the container and then insert oxygen sensors and carbon dioxide sensors in the holes. 2) Burn a candle in the container and observe the changes in the burning of the candle. The experiment has checked oxygen concentration and carbon dioxide concentration in real-time and displays gas concentration changes by graphs. The results of the application effect of the experiment are as follows. Most elementary school teachers who had not had scientific concepts on combustion got acquainted with scientific concepts about the reason why a candle is blown out when it is covered with a bottle, and the concentrations of oxygen and carbon dioxide before and after combustion. In addition, about half of elementary school teachers got acquainted with scientific concepts about the definition of combustion, and distribution of carbon dioxide during combustion. Thus, the experiment to measure gas concentrations during combustion is helpful to improve elementary school teachers concepts on combustion.