Science - Chemistry
Standard 3 Objective 3
1 class periods of 45 minutes each
In this activity, students build models of polarized water molecules using K'Nex toy components and adhesive Velcro. Students investigate hydrogen bonding by shaking the models in various ways. They observe the resulting interactions and relate their observations to physical states of water and the difference between strong bonds and weak attractions.
K'Nex does not make kits for the models described in this Activity. The needed K'Nex components could be ordered individually from K'Nex; part numbers for the needed components are below. Kits of K'Nex to build 100 models (enough for ~15 groups of students) are available from the Bloomsburg University Mathematics and Science Learning Center for a nominal cost plus shipping; contact:
Emeric SchultzVelcro with adhesive backing is available in fabric or craft stores. Whole black loop circles (~1.5 cm diameter) can be used for electron pairs on oxygen. Strips of white hook Velcro can be cut up for the partial positive charge on the hydrogens. The hook Velcro should be trimmed to just cover the ends of the hydrogen K'Nex connector to minimize non hydrogen-bonding connections. The most common unwanted event is the connection of two hydrogens to one oxygen electron pair. Over time, there may be degradation of the Velcro and adhesive backing, resulting in the Velcro not connecting correctly or the Velcro falling off the models. "Super glue" can be used in these cases.
Department of Chemistry
Bloomsburg, PA 17815
All instructional procedures are detailed on the student sheet attached.
Scoring Rubric or answer key:
Adapted from "The Nature of Hydrogen Bonding" by Schultz, Emeric. J. Chem. Educ. 2005 82 400A.
Lesson Design by Jordan School District Teachers and Staff.