10 periodic tables for a year filled with chemistry. A revision of the International Year of the Periodic Table in secondary schools in Catalonia

Many schools have joined the celebration of the International Year of the Periodic Table (AITP) and have carried out a wide variety of activities and initiatives, especially in secondary schools. One of the main activities has been to involve students in the elaboration of all kinds of periodic tables, and many classrooms, corridors and facades of educational centers have been filled with names of chemical elements, atomic numbers, groups and periods. But how are these tables? In this article, and following Mendelieviev's desire to classify and order, we wanted to synthesise the various products that were generated in the school context. The aim of this collection is to recognize the work of all the teachers involved, and at the same time take the opportunity to reflect on the teaching and learning of chemistry based on the contributions of the various proposals made.