Abstract
This study examines teaching of the rule 'all matter can undergo phase transitions (solid⇔liquid⇔gas)'. The hypotheses were, (1) before teaching the rule, many pupils have some misunderstandings about phase transitions and (2) the misunderstandings can be cleared by presenting examples in addition to water. Thirty-two fourth graders participated in the pre-test, teaching and post-test. The results were as follows: (1) before teaching, some students had misunderstandings such as 'some substances don't undergo phase transitions'; (2) the misunderstandings can be eliminated by presenting examples of substances other than water; (3) phase transitions of water were adequately learnt; and (4) 54% of the participants understood the principle as demonstrated by the fact that they were able to apply the rule consistently. These results confirm only the first hypothesis and the teaching plan needs some reconsideration, especially on the part concerning the transition between liquid and gaseous phases.
