Abstract:
This thesis is a report on a comparative study of diagrams and models used as teaching aids in teaching atomic orbitals in senior secondary schools (SSS). An orbial represents a three-dimensional volume of space around an atomic nucleus, where electrons are found. Diagrams of orbitals in textbooks and on teachers' chalkboards appear in two dimensions, making visualization difficult for students.
Three second-year elective chemistry classes in different schools in the Cape Coast Municipality were pretested on atomic orbitals. They were then taught the concept of atomic orbital, using diagrams only, models only, and a combination of diagrams and models respectively as teaching aids. Finally, they were posttested on the concept.
Analysis of covariance (ANCQY A) on the posttest scores of the students, using their pretest scores as covariate, ranked the teaching aids in the order: "models only", "diagrams and models" and "diagrams only". A McNemar chi- square test on changes in students' misconceptions from the pretest to the posttest showed that the "models only" class had the highest signi ficant proportional decrease in misconceptions, whilst the "diagrams only" class had the least.
It is therefore concluded that the use of models only as teaching aids is more effective than the use of diagrams only in enhancing SSS students' visualization of atomic orbitals. Moreover, combination of diagrams and models confuses students and hampers their visualization Suggestions have therefore been made in the thesis for appropriate bodies to emphasize the use of' models in teaching atomic orbitals to SSS students.
