Abstract
Electrochemical series of metals is an important topic within all levels of the chemistry teaching. This chapter is focused on the combination of common teaching topic and enquirybased science education approach with mystery incorporated.
It deals with a teaching material for the laboratory course, which could be used as a laboratory theme for teachers not only at secondary schools and which was developed in the framework of the TEMI project. At the beginning, pupils actively familiarize with the story about murders of the goldsmith and jeweler Beketov and the police commissioner Markovnikov.
In the second part, they finish experiments which lead to revelation of the murder. At the end, on the basis of the chemical experiments made by pupils, they expose the murderer.
Supplier of metals killed Beketov and Markovnikov as they recognized that the supplied metals were not the noble metals. The material uses IBSE approach following 5E-cycle and it was positively evaluated by pupils participating the lab course.