Full text
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| Author(s): |
Helena Savignani Alvares Nogueira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Física (IF/SBI) |
| Defense date: | 2018-10-02 |
| Examining board members: |
Paulo Alves Porto;
Andréa Bortolotto;
Helio Elael Bonini Viana
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| Advisor: | Paulo Alves Porto |
| Abstract | |
This dissertation analyzes the approaches to the concept of valence in university-level general chemistry textbooks published in the USA throughout the first decades of the twentieth century. A historical case study about the development of the concept of valence in late nineteenth and early twentieth century is presented. It is shown that the concept of valence emerged from two theories on the combination of elements: the theory of types and the theory of radicals. Other important points from the historical case study were the involvement of several scientists from various countries and the relationship between the concept of valence and studies on chemical bonding, periodicity and chemical structure. Changes in nomenclature and notation for valence were also noted. In a second moment, the presence of the concept of valence in selected textbooks was investigated, by means of a qualitative analysis based on discursive textual analysis. The criteria for analysis included: location of the subject in the textbook; nomenclature and notation used; definition provided and whether it is linked to some historical, mathematical or experimental method of determination; presence of the historical context and the development of the concept over the years; which subjects are related to valence; and which uses and applications were given to valence in the textbooks. The main results of such analysis include: the absence of in-depth discussions about the history of science; the importance given to the concept of valence by the authors; the existence of a transition period from the classical to the electronic concept of valence, which occurred shortly after the construction of the electronic concept by scientists; and a shift in the focus of chemical science presented in the textbooks, which gradually fail to recognize the existence of uncertainties and gaps in chemical knowledge. (AU) | |
| FAPESP's process: | 16/09213-5 - The concept of valence in university-level general chemistry textbooks in the twentieth century |
| Grantee: | Helena Savignani Alvares Nogueira |
| Support Opportunities: | Scholarships in Brazil - Master |