College Students’ Conceptions of Chemical Stability: The widespread adoption of a heuristic rule out of context and beyond its range of application
College Students’ Conceptions of Chemical Stability: The widespread adoption of a heuristic rule out of context and beyond its range of application
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大学生对化学稳定性的认识：断章取义、超出应用范围的启发式规则的广泛采用
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发表时间：
2009
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影响因子：
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通讯作者：
K. Taber
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作者：
K. Taber
本文报告的证据表明，学习者通常发展的化学稳定性的概念，而在课程中教的想法，但与基本的科学原理不一致。一系列相关的小规模研究表明，许多大学生认为具有八隅体结构或完整外壳的化学物质必然比没有这种电子构型的相关物质更稳定。虽然这一发现本身与以前的研究是一致的，本文显示了学生如何普遍适用于这一标准，而不考虑化学背景，或其他重要因素，如净电荷。从化学角度来看，那些看起来非常不稳定和不可行的物种，如Na 7 −，C4+甚至Cl 11 −，通常被认为是稳定的。这项研究表明，当被问及化学物种在亚微观水平上的稳定性时，许多大学生正在接受一个简单的启发式（具有完整外壳的物种将是稳定的），而排除了更相关的考虑因素。有些学生甚至会认为处于激发态的原子比处于基态时更稳定，基态时电子从内层被提升到“填充”外层。有人建议，显然是广泛采用的观点，这是在不符合科学的课程是非常重要的化学教学，并表明需要更详细的研究，这种思维如何发展，可以受到挑战。
This paper reports evidence that learners commonly develop a notion of chemical stability that, whilst drawing upon ideas taught in the curriculum, is nevertheless inconsistent with basic scientific principles. A series of related small‐scale studies show that many college‐level students consider a chemical species with an octet structure, or a full outer shell, will necessarily be more stable than a related species without such an electronic configuration. Whilst this finding is in itself consistent with previous research, the present paper shows how students commonly apply this criterion without consideration of chemical context, or other significant factors such as net charge. Species that would seem highly unstable and non‐viable from chemical considerations, such as Na7−, C4+ and even Cl11−, are commonly judged as being stable. This research shows that many college‐level students are privileging a simple heuristic (species with full outer shells will be stable) when asked about the stability of chemical species at the submicroscopic level, to the exclusion of more pertinent considerations. Some students will even judge an atom in an excited state as more stable than when in the ground state, when an electron is promoted from an inner shell to ‘fill’ the outer shell. It is suggested that the apparently widespread adoption of a perspective that is so at odds with the science in the curriculum is highly significant for the teaching of chemistry, and indicates the need for more detailed studies of how such thinking develops and can be challenged.