Students come across radioactivity as a theme in the curriculum of physics in the third class at the end of the school year. Because of overfull curriculum, professors usually pass the radioactivity theme into the fourth year, when students prepare themselves for a final physics exam, a part of matura. Only these students are acquainted with this topics and the rest of student population does not come across with radioactivity at all.
Many different researchers from the eighties and more recent periods concluded that students and general public do not understand scientific terms and concepts, which effects on perception of media news and fear. Accordingly to curriculum, students get the knowledge about different radioactive decays. However, based on my experiences and professors' claims, this knowledge is not enough for understanding the radioactivity phenomena. Consequently, for everyday's life, students do not have enough knowledge and abilities to cope with sensational media news about nuclear accidents and radiation in general.
Tested and developed activity about radioactivity encourages professors to upgrade their teaching about different radioactive decays. They can use the template of activity that is elaborated here, which takes two school hours. At the same time, they will enable students greater knowledge about radioactivity, about safety measures, ionizing radiation and simultaneously, students will get the opportunity to develop critical thinking and judging. Activity was tested in three classrooms of Gimnazija Bežigrad. Participant observation, real-time evaluations with the students, self-evaluation and interviews with teachers were used to analyse the testing. Results show that the activity is suitable for the third year's students for the end of the school year. Activity creates relax atmosphere because of its incomplexity and at the same time, it is full of physics content. Analyses showed that students did successfully solve the problems with teamwork, even though they are not used to work in groups and they have different prior knowledge, too. I also researched how different instructions effect on teamwork. Better structured and articulated instructions for the problem that can be applied in everyday's life have a stronger effect on group motivation. Students are more focused on a problem solving and their answers are explained and justified. In addition to the content of the activity, I bore in mind also a technical aspect. All schools do not have the same inventory, which will enable the execution of any kind of experiment. Therefore I tried to design the activity with basic technical things, for example, a radiation detector, radioactive materials and different layers for absorption. For activity, a spark counter is needed too. However, making is not complicated because it has only a few elements. At the same time, an alternative is presented, which does not require a spark counter. Additionally, a list of companies states the best possibilities for schools' purchases, if they decide to buy new inventory.