Orbitals in chemical education. An analysis through their graphical representations

Abstract

Students' understanding of the orbital concept has been subject to considerable research and debate and often found at variance with a quantum mechanical ideal. Could it be the case that orbitals as actually used by practising chemists in teaching and research also differ from that ideal? Our experience shows that this might often be the case. Through a series of examples of pictorial representations of orbitals found in textbooks and other educational materials, as well as in research papers, we argue that this is a common situation, which deserves to be stated explicitly. We point out that, in particular, there is a way in which orbitals are frequently employed deeply rooted in chemical thinking and compatible with a classical (in the sense of pre-quantum) approach. Many chemists employ quantum-like terms, and rely on concepts that look quantum, such as ‘orbital’, but they actually play on the well-known ground of the classical structural ideas that can be traced back to the work of pioneers like Cannizaro, Kekulé, or van't Hoff. We maintain that given the fundamental role of these semi-classical ideas in chemistry, it is nothing but natural to treat them in an equivalent fashion in chemical education.

Orbital Atômico: Conceitos, Ontologia e Ensino

“…Consideramos de especial relevância a constatação de que estudantes de graduação em Química não desenvolvem a percepção de que há (ao menos) dois conceitos de orbital atômico (Lima & Silva, 2019;Tsarpalis & Papaphotis, 2002): (a) como função de onda monoeletrônica em um átomo, e (b) como região do espaço onde há alta probabilidade de encontrar o elétron em torno do núcleo atômico. Ademais, alega-se que o conceito de orbital como região do espaço está impregnado de um modo de pensar realista acrítico (Barradas-Solas & Sánchez Gómez, 2014;Scerri, 2000a).…”

Pesquisa Bibliográfica: As Reações De Oxirredução De Acordo Com Os Modelos Mentais

“…Identificação do artigo 03, 05, 06, 09, 14, 16, 18, 20, 21, 22, 23, 29, 31, 35, 36, 38, 44 e 52 02, 04, 08, 11, 12, 17, 25, 28, 33, 42, 45 Os demais vinte e quatro artigos, isto é, 12,07,10,13,15,19,24,26,27,30,34,32,37,39,40,43,46,47,49,50,51,53, 54 e 55, por apresentarem um contexto mais geral ou por serem teóricos, não constam nessa divisão de subáreas.…”

“…O Quadro 8 mostra os trabalhos presentes em cada um dos quatro Níveis estabelecidos. 04,05,06,07,09,13,14,15,17,18,19,21,22,23,24,26,27,28,30,32,34,35,36,37,38,39,40,42,43,44,46,47,48,49,50,51,52,53,54 Conforme já mencionado, no decorrer da análise destes quatro Níveis, categorias e subcategorias emergentes foram elaboradas, desconsiderando-se aquelas formadas por apenas um artigo. Salienta-se ainda que, pelo fato de todas as cinquenta e seis publicações abordarem os modelos mentais e as reações de oxirredução, mesmo que de forma simplória e desconexa, algumas categorias e/ou subcategorias constam em mais de um Nível e que um mesmo artigo pode estar presente em mais de uma categoria e/ou subcategoria (desde que em um mesmo Nível).…”

Library of 3D Visual Teaching Tools for the Chemistry Classroom Accessible via Sketchfab and Viewable in Augmented Reality

“…Teaching in a purely virtual setting as a consequence of the COVID-19 pandemic has encouraged the invention and adoption of new visualization tools. , Previous efforts have built libraries of freely accessible online teaching resources for chemistry. − These tools are particularly vital for a hands-on science like chemistry, in which the act of physically manipulating molecular models can be crucial for understanding spatial relationships. − For this purpose, molecular model kits, computational chemistry programs, and augmented reality tools have been increasingly introduced into the general chemistry classroom as teaching tools. − Model kits enable students to craft molecules physically, thereby discovering things like the effect of steric encumbrance, rotation about single bonds versus double bonds, and the nonsuperposition of enantiomers. Augmented reality offers a middle ground between the intangible computer-generated images and the tactile nature of model kits. − By coupling this tactile learning with visualization of the complex geometries inherent to molecular orbitals, students achieve a more holistic view of bonding in chemistry. − Unfortunately, computational chemistry tools often have a steep learning curve, may lack compatibility across operating systems and devices, and may require technical capabilities that many students lack .…”