Introducing UV–visible spectroscopy at high school level following the historical evolution of spectroscopic instruments: a proposal for chemistry teachers

Spectroscopy is a scientific topic at the interface between Chemistry and Physics, which is taught at high school level in relation with its fundamental applications in Analytical Chemistry. In the first part of the paper, the topic of spectroscopy is analyzed having in mind the well-known Johnstone’s triangle of chemistry education, putting in evidence the way spectroscopy is usually taught at the three levels of chemical knowledge: macroscopic/phenomenological, sub-microscopic/molecular and symbolic ones. Among these three levels, following Johnstone’s recommendations the macroscopic one is the most useful for high school students who learn spectroscopy for the first time. Starting from these premises, in the second part of the paper, we propose a didactic sequence which is inspired by the historical evolution of spectroscopic instruments from the first spectroscopes invented by Gustav Kirchhoff and Robert Bunsen in 1860 to the UV–vis spectrophotometers which became common since the 1960s. The idea behind our research is to analyze the conceptual advancements through the history of spectroscopy and to identify the key episodes/experiments and spectroscopic instruments. For each of them, a didactic activity, typically an experiment, is then proposed underlining the relevant aspects from the chemistry education point of view. The present paper is the occasion to reflect on the potentialities of an historical approach combined with a laboratorial one, and to discuss the role of historical instruments and related technological improvements to teach spectroscopy.