Enhancing sub-micro level understanding

This study explores how prospective primary school teachers explain the boiling of water at the sub-micro level during and after participating in a compulsory science education course (chemistry and physics) in Finland. Data were collected from 50 prospective primary school teachers and consists of worksheets, written exam answers and illustrations. The analysis focuses on the development of the use of key scientific concepts—related to the phase changes of water—and the ability to distinguish between macro and sub-micro levels when explaining phase changes of water. The results revealed limited use of scientifically accurate terminology, with fewer than one-third of prospective primary school teachers using the correct concepts. Many responses included vague or ambiguous descriptions of particle behaviour. By the end of the course, a significant improvement was observed in how they used the key concepts related to the phase change(s) of water. Despite gains in use of correct terminology, still many prospective primary school teachers continued to confuse observable phenomena with molecular-level processes. A more fine-grained analysis shows that although they use key concepts that refer to the sub-micro level both in worksheets and exam answers only half of them can explain more precisely what occurs at the sub-micro level. Illustrations of the sub-micro level also varied in accuracy, only a few (10%) included correct intermolecular forces (hydrogen bonds) between the molecules in their illustrations.