Research on teachers’ and students’ conceptions of science, and their roles in teaching and learning science, has become of the most important research domains in education and has a strong history in Australia and New Zealand. Exploring students’ mental states during the teaching and learning of acids and bases is important to facilitate conceptual change. Science teachers know very well that students’ interests, enjoyment, willingness, intentions, needs and motivation for learning science are important issues to consider in the classroom, because they are indications of how students perceive the lesson being taught. Many teachers are intuitively constructivist in their approach to teaching—for example, they want to be able to assist students in their learning, and they are aware of the importance of students’ cognitive activity and observations. The extensive and accepted process of using models for explanations has made the models appear as fact to many teachers and students.