The purpose of this study is to assess young children’s understanding of the properties of air, and to demonstrate Predict-Observe-Explain (POE) activities developed to improve their understanding. Good instructional models, such as POE, may help young children better understand abstract and invisible physical phenomena like air. POE activities create a prediction-outcome conflict that helps children to rethink and reorganize what they observe. Before performing POE experiments, the majority of young children did not think that air is everywhere; 89% of children believed that there is air in their noses, but 64% contended that there is no air in an open container. After reaching successively contradictory judgments in POE activities, 36% of children changed their initial, incorrect ideas about air. Although there was some modest success achieved in this study, for children obtaining consistent and holistic concepts in science is a long-lasting process. The conclusion of this study suggests that preschool children can benefit from a wide range of POE activities in different topics, especially in physical sciences because with professional guided learning they are more likely to develop a correct understanding of scientific concepts.