2021 Volume 62 Issue 2 Pages 485-495
In the study of radiation in junior high school science, although the number of classes conducting cloud chamber experiments is increasing, it has not been investigated whether the students fully understand the meaning of the cloud chamber experiment or its various operations. In this study, we conducted a cloud chamber experiment in a class learning about radiation and investigated the actual state of the students’ understanding of various aspects of the experiment from a number of perspectives via the administration of a questionnaire survey and interview survey. The results of our analysis clearly show the following four points: 1. About 80% of the students who participated in the experiment answered that the “radiation trail” was “radiation”. 2. About 60% of the students who participated in the experiment did not understand the meaning of important experimental operations such as why ethanol is added, the purpose of cooling with dry ice, and why the cloud chamber is sealed. 3. Even students who have a correct prior understanding the invisibility of radiation and its penetrating power will overturn it and misunderstand after conducting the cloud chamber experiment. 4. Even when the cloud chamber experiment is carried out successfully, the students misunderstand the nature of radiation by misapplying the phenomenon that occurred in the cloud chamber experiment to their experience of daily life.
