1. Pavol Jozef Šafárik University in Košice, Lifelong Learning Centre and Project Support, Šrobárova 2, Košice 041 80, Slovakia
2. Jagiellonian University, Faculty of Chemistry, Department of Chemical Education, Gronostajowa Str. 2, Kraków 30-387, Poland
3. Pavol Jozef Šafárik University in Košice, Faculty of Science, Department of Didactics of Chemistry, Šrobarová 2, Košice 041 80, Slovakia