This is a simple third grade activity that covers the following standards:
-Earth’s nonliving resources have specific properties.
-All objects and substances in the natural world are composed of matter.
-•Matter takes up space and has mass*.
(While mass is the scientifically correct term to use in this context, the NAEP 2009 Science Framework (page 27) recommends using the more familiar term "weight" in the elementary grades with the distinction between mass and weight being introduced at the middle school level.)
Prior to this activity, students needs to collect two rocks that will fit into available containers of water. The students, draw, measure, compare, and answer questions about the rocks' properties, similarities, and differences.