This curriculum unit is for use in an elementary school foreign language immersion program in Montgomery County, Maryland. The unit is geared toward the second grade science classroom. It includes instructional and performance objectives, vocabulary lists, optional language structure sections, illustrations, activities, evaluation suggestions, and worksheets. The unit considers the interrelationships of light and shadow, changes caused by the interactions of matter, and the behavior of liquids as they interact with different kinds of surfaces. With the exception of instructional objectives, all materials are written in Spanish. (SR)