Using these theoretical foundations, ten narratives were selected or constructed in
order to work with science teachers along the unit; they are stories borrowed from
other authors, adaptations, or materials purposefully created for the unit. The
narratives are introduced in step 6 of the unit (see above), as epitomes of scientific
activity for NOS analysis; they serve as vehicles both for the scientific and the
historical information. As it was advanced, the narratives are mainly connected to
the topics of structure of matter, atomic theory, and radioactivity (see Adu´riz-Bravo
2005a, b, 2014; Adu´riz-Bravo and Bonan 2006; Adu´riz-Bravo and Izquierdo-
Aymerich 2009). They include ‘classic’ episodes (e.g. Dalton’s conception of the