Scientific modeling along with hands-on inquiry can lead to a deeper understanding of scientific concepts among students in upper elementary grades. Even though scientific modeling involves abstract-thinking processes, can students in younger elementary grades successfully participate in scientific modeling? Scientific modeling, like all other aspects of scientific inquiry, has to be developed. This article clearly outlines how students in a first-grade classroom can develop and use scientific models to explain the properties and behaviors of solids, liquids, and gases in a unit on the states of matter. (Contains 5 tables, 7 figures, and 1 note.)