Young students need opportunities to develop their conceptual understanding of properties of matter. By providing students with inquiry activities, we lay the groundwork necessary for students to grasp the challenging concepts associated with learning about the periodic table in middle school. In this 5E activity (Bybee 2009), fifth-grade students assume the roles of environmental engineers to clean up contaminated soil. They are tasked with identifying unique properties of components of a mixture in order to select appropriate tools for separating these components. Development of the vocabulary word property as it is used in the context of matter frames the conceptual understanding that matter has unique properties that can be leveraged to separate a mixture. Once students develop a plan to separate their mixtures, they select tools such as magnets, sifters, and tubs of water to perform the task. After their mixtures are separated, the activity is extended by providing students the opportunity to find the mass of each component using digital scales. Throughout the activity, probing questions help guide the students. Opportunities to develop vocabulary are interwoven throughout this engaging lesson.