The evaluation of green chemistry principles in the primary school experimental work by the use of the Green star method

In accordance with the Chemistry Curriculum the teachers' assignment is by the Experimental Work to accustom students in a consistent and systematic enforcement of hazardous properties of the substance responsible use of materials, appropriate waste disposal and proper use of protective equipment (Bačnik et al., 2011). Bodner (2015) suggests that we include the socio-natural context in teaching Chemistry and with appropriate adjustments to Experimental Work we develop students' understanding of Green Chemistry (eg. using reactants from renewable sources, performing microexperiments, experimentation in groups). Teachers can also contribute to raising awareness of students for responsible behavior in the field of Chemical Safety in Chemistry, taking into account 12 Principles of Green Chemistry, eg. by evaluating the environmental suitability of the Experimental Work using the stoichiometric calculation of surplus reagents, studying the reaction conditions, studying the performance of the Experimental Work in terms of environmental hazards, human health and possible accidents, waste hazardous substances, studying the possibility of converting waste materials into harmless products and their reuse, synthesis of derivatives and the like (Duarte, Ribeiro and Machado, 2014; 2015). The environmental suitability of the Experimental Work can be visualized with the Green Circle metric and the Green Star metric (Ribeiro, Costa and Machado, 2014), which are based on the Evaluation of the 12 Principles of Green Chemistry. In the Master's thesis, the Green Circle metric and the Green Star metric were used, developed by Ribeiro, Costa and Machado (2010) to evaluate and optimize Experimental Work at school. In the master's thesis, 30 randomly selected experiments in the field of organic chemistry from Slovene Primary School textbooks, which were confirmed for the school year 2017/2018, were examined. We focused on a section of organic chemistry following study groups: Family hydrocarbon polymers, Oxygen family of organic compounds and Nitrogen family of organic compounds. The results show that more than half of the studied set of experiments teaching Nitrogen family of organic compounds, Chemistry Curriculum in elementary school take into account the Principles of Green Chemistry in relation to the metric Green Circle and metric Green Star. Because of using chemicals that have hazardous properties the results indicate the minimal consideration of the Principles of Green Chemistry in the studied experiments of the study group Hydrocarbon Family with polymers, a chemistry curriculum in elementary school. Optimization options were also considered for the three selected examples of experiments. Based on the results of the master's thesis and in accordance with the requirements of the Principles of Green Chemistry it is sensible to stimulate thinking about the need to optimize school Experimental Work also on a wider scale