摘要：The purpose of this work is to study the level of misconceptions among the students of class IXth grade about the unit structure of atom and the remedial measures of these misconceptions. The sample consisted of 189 students. The research has carried out with two groups' pre test post test control group design during four weeks. After administering entry level test, the experimental group was taught with illustrative materials, as remedial measure, containing various atomic model and then criterion referenced test (CRT) was administered on the same unit to collect the data. Paired sample't' test was used to compare the results obtained from entry level test and CRT using SPSS-16 software. The results from the post-tests indicated that the students in the experimental group, taught with the illustrative material, showed a significant decrease in misconception level than the students in the control group. These results show that the implementation of the new material produced better results in terms of achievement of the student.
