The aim of this paper is to analyse the use of subject-specific concepts in chemistry books within a chosen topic. The following questions have been formulated:

• What subject-specific concepts are present and with what frequency?
• In what way, do they clarify the subject-specific concepts?

To achieve the purpose and the issues raised in the paper, the chapter will be analysed with two different content analysis. The material will then be analysed based on Vygotsky's theory of the development of scientific concepts.The results show that the chapters use different subject-specific concept.

In addition, the amount also varied significantly. The frequency of the subject-specific concepts was low in all three chapters. The chapter had a large variety of representations, but the chapters showed no resemblance to how they were clarified. The study can be interpreted as demonstrating that the textbooks have very different subject content, which in turn, given the role of the textbook in the study, can influence the subject knowledge acquired as a student.