The aim of this study was to compare the 5E learning model with traditional learning methods in terms of their effect on students' conceptual understanding of water subtopics. The participants of the study were grade 8 students of 2021 academic year. While 27 of them were randomly assigned to the experimental group, the other 27 were assigned to the control group. The experimental groups were taught with 5E instructional model of the constructivist approach, whereas the students in the control group were taught with the traditional approach. Both qualitative and quantitative research methods were used in this study. Research questions were answered using mean and standard deviation, while the null hypotheses were tested using t-test at 0.05 significance level. The results from pre-tests showed that there was no significant difference between the control group and the experimental group. On the other hand, the post-test results showed that there was a significant difference between groups in favor of the experimental group. Also, the experimental group's perception of motivation in classroom learning environment during the treatment was higher than that of the control group. It is essential that teachers should develop their skills for designing a constructivist-learning environment within class. With this aim, teachers should be given in-service training.