Structure-property reasoning (SPR) is one of the most important aims of chemistry education but is seldom explicitly taught, and students find structure-property reasoning difficult. This study assessed two design principles for the development of structure-property reasoning in the context of demonstrations: (1) use of a POE task (predict-observe-explain) and (2) use of the domain-specific particle perspective, both to increase student engagement and to scaffold micro-level modeling. The aim of the demonstration series was to teach structure-property reasoning more explicitly to pre-university students (aged 15-16). Demonstrations pertained to the properties of metals, salts and molecular compounds. The SPR instrument was used as a pretest and posttest in order to gain insight into the effects on structure-property reasoning. In addition, one student (Sally) was followed closely to see how her structure-property reasoning evolved throughout the demonstrations. Results show that after the demonstrations students were more aware of the structure models at the micro-level. The students also knew and understood more chemical concepts needed for structure-property reasoning. Sally's qualitative data additionally showed how she made interesting progress in modeling micro-level chemical structures. As we used conventional demonstrations as a starting point for design, this could well serve as a practical tool for teachers to redesign their existing demonstrations.