2014 Volume 54 Issue 3 Pages 335-346
In this study, we have introduced a concept of particles first into the “water and steam” unit in the fourth grade of the elementary school and then applied this concept to the “dissolution” unit in the fifth grade. Through this classstudy, we have paid attention mostly to the following two points: making the class content as simple as possible and solving problems by use of a scientifically correct particle model. Then we have examined whether a child at the elementary school stage could effectively use the knowledge of particles acquired in the previous study. In this article, we describe the reason why we chose the “water and steam” unit as the scene to introduce the concept of particles to the elementary school students for the first time. Then, we report the results for our teaching practice.The suggestion that a teacher gave fourth grade children is only “all the materials are comprised of invisible small particles” and “the size of the particles does not change”. By using these clues, children solved a problem “whereas the water is visible, why is the steam invisible?”. The next year, the same children learned about the uniformity of dissolution by using the knowledge obtained in the former study. Their understanding of the learning contents was very good. Therefore, we concluded that children were able to form an image of the solution by the particle model.
