Practical Research on the Particle Model's Understanding

Abstract

In the "dissolution" unit for the first year of lower secondary school, much research was conducted about recognition of particle models during guidance. This is practical research which improved educational guidance based on the actual status of students measured by the research. If we on ly presented the explanation about particles in a text book, the number of students who were able to explain the particle model in a water solution was about half. It can be assumed that many students did not understand the existence of particles in a water solution. After learning the size, mass and characteristics of particles in a water solution, students recognized the existence of particles in a water solution and became able to explain particle models. However, half of the students did not distinguish visible grains of sugar and the minimum grains in a water solution which cannot be broken down and expressed both of them by using the same "○" symbols. Then, we gave guidance about handling of particle models together with learning of size, mass and characteristics of particles in a water solution. As a result, about 70% of the students became able to express correct particle models. According to the above, it was pointed out that the learning of the existence and characteristics of molecule level particles as well as learning how to apply particle models was required for scientific understanding of particle models. On the other hand, there were students who questioned about replacing in visible particles with models and therefore, how to give guidance to them is another challenge.