Chemistry is often regarded as a complex and demanding subject for youth to learn, partly because of abstract concepts that are challenging to depict. These areas require spatial reasoning, defined as the ability to retain, generate and manipulate abstract visual images in space, either physically or mentally. By allowing the superimposition of virtual objects in the real world, Augmented Reality (AR) facilitates students’ understanding of difficult concepts through spatial reasoning by making them visible and allowing for multidimensional perspectives. “Periodic Fable” is an AR serious game targeting 8 to 11-year-old children, designed to teach them basic chemistry concepts of the Periodic Table of Elements in non-formal settings. After designing and implementing the game, we conducted an exploratory study with 36 young participants, using a mixed-method approach. A comparative study between pre- and post-intervention questionnaires and observation results shows a positive learning outcome, demonstrating the potential of this tool in a non-formal context.