Banca de DEFESA: LUCAS DOS SANTOS FERNANDES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LUCAS DOS SANTOS FERNANDES
DATA : 02/12/2019
HORA: 14:00
LOCAL: Instituto de Química - Sala de Seminários (3o andar)
TÍTULO:

CONCEPTUALIZATION OF COVALENT BONDING BY CHEMISTRY UNDERGRADUATES

PALAVRAS-CHAVES:

Covalent bond. Scientific concept. Conceptual system.

PÁGINAS: 125
GRANDE ÁREA: Ciências Humanas
ÁREA: Educação
SUBÁREA: Ensino-Aprendizagem
RESUMO:

This research refers to a study on the concept of covalent bonding. National and international works reveal that this concept is poorly studied in detail and that there are many alternative conceptions associated with it. Added to this is the importance of understanding this concept for the learning of other chemical contents, such as enthalpies of binding, reaction mechanisms and submicroscopic structure of matter. These reasons justified this study, whose main objective was to understand how undergraduates in chemistry conceptualize covalent bonding and employ this concept in solving chemical problems. The concept of covalent bonding can be approached in chemistry teaching according to the classical and quantum models, although often the distinction between the two is not evident. To explain the conceptualization of covalent bonding, Vygotsky's theory of the formation and development of everyday and scientific concepts was used. Each concept corresponds to the meaning of words and can be defined by their characteristics, which form a conceptual system. The characteristics of covalent bonding are: electron sharing, stability, high internuclear electron density, bonding energy, length, direction, multiplicity, polarity, orbital overlap, spins pairing and resonance. The methodology of this research is qualitative and corresponds to an explanatory study. Thirteen students from the last semester of the Chemistry Degree course participated in this study. Data were collected through questionnaire and interviews. Data analysis was performed searching the terms or expressions related to the concept of covalent bonding and its characteristics. Comparing the characteristics of the covalent bond that make up the concept map elaborated in this research with the students' answers, it was noticed that their conceptual system is limited to a few concepts: electron sharing, orbital overlap and stability, with possible citations about other characteristics, including alternative and misconceptions. Few conceptual relationships result and a poor conceptual system. Such system proved to be hybrid because it presents characteristics of the classic and quantum covalent bonding models. This suggests that the concept of covalent bonding was partially learned by the students investigated. The results point to the need to improve the teaching of covalent bonding in the initial formation of chemistry teachers. A point that seems crucial to us is the articulation of the disciplines that work with this concept. Despite the limitation, the hybrid conceptual system presented by the students is consistent with what is practiced at the level of education in which they teach. However, it is recommended that covalent bonding teaching favor the quantum model as it offers more tools for understanding the submicroscopic structure of matter. In addition, covalent bonding must distinguish between classical and quantum models and be appropriate to the level of education, the atomic model previously addressed, and the level of cognitive development of students.

MEMBROS DA BANCA:
Presidente - 071.811.595-34 - JOSE LUIS DE PAULA BARROS SILVA - UFBA
Interno - 2895880 - HELIO DA SILVA MESSEDER NETO
Externo ao Programa - 1877452 - ISADORA MELO GONZALEZ
Externo à Instituição - ÂNGELA FERNANDES CAMPOS - UFRPE
Externo à Instituição - ABRAAO FELIX DA PENHA - UNEB