Teachers’ understanding of the particulate nature of matter: The case of Zambian pre-service science teachers

The purpose of this study was to assess Zambian junior high school science pre-service teachers’ understanding of the particulate nature of matter. The findings of this study were also compared to those reported in previous studies on teachers’ conceptions of the particulate nature of matter. The results show that most teachers had correct views on the effect of phase change on speed, spaces and number of particles of a substance. They displayed better understanding on number, speed, size of particles and spaces between particles when solids and liquids are compressed. This group of teachers correctly believed that matter can be compressed including solids and liquids though the extents to which different solids can be compressed vary. However, most pre-service teachers had poor understanding about the effect of phase change on the size of the particles in solid, liquid and gas. Furthermore, this study confirmed some findings reported in previous studies. For example, the pre-service teachers in this study also believed that heating a substance cause the size of its particles to increase while cooling it makes the particles decrease in size. As such, we can conclude that this group of teachers believed that when a substance is heated it expands due to the expansion of its particles [atoms or molecules], and when a substance is cooled it contracts because the size of the particles [atoms or molecules] decrease.