This study aims to explore the implications of presenting the particulate nature of matter in ways that are appropriate for elementary students’ developmental characteristics and for elementary science education. This study analyzed the presence of illustrations depicting particles, as well as their accompanying descriptions in elementary-level science textbooks used in Korea, the United States, Finland, and Japan. Additionally, a survey was conducted with 43 teachers employed at seven elementary schools in Gyeonggi-do, followed by an in-depth interview with a head teacher to gain a pedagogical perspective on scientific illustrations and their use. Textbooks from the United States, Finland, and Japan contained illustrations depicting the place of particles in the natural world. In contrast, Korean textbooks contained no such illustrations. Teacher surveys and in-depth interviews revealed that respondents considered illustrations featuring particles to be appropriate for elementary students’ developmental levels. Furthermore, a significant number of respondents indicated that illustrations in general, both with and without particles, are helpful and appropriate for elementary-level science education. Therefore, this study offers implications for curriculum and textbook development that prioritize internal variables—such as elementary students’ developmental levels and the essential characteristics of elementary science education—over external variables, such as the coordination of learning content with upper grades or workload adjustments.