Interactions: Student Understanding of Intermolecular Forces

The Interactions project is developing and testing web-based instructional materials for high school students in physical science courses. These materials enable students to develop an understanding of the forces and energy involved in the interactions of atoms and molecules. The year-long curriculum can be used in a physical science, chemistry or physics class.   In particular, students will:
  • develop and use models of interactions taking place at the atomic and molecular scale to explain things they can observe in the world around them, and
  • develop a model that can explain the flow of energy and cycles of matter for things taking place on both the macroscopic and sub-microscopic scales
  Meeting these goals will help students build a foundation for success across all science disciplines by preparing them to explain and make predictions about important phenomena.   The design principles and goals used to guide the development of the materials include:
  • Building student understanding of ideas within and across units
  • Explicitly stating learning performances to guide the development of learning and assessment tasks
  • Engaging students in scientific practices
  • Engagement with phenomena to help illustrate and involve students with disciplinary core ideas
  • Physical models and computer simulations to help students connect observable phenomena with sub-microscopic mechanisms
  • Reading materials that support understanding by building on in-class experiences

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The curriculum consists of units that focus on answering a question designed to engage students in the learning goal and help them relate and build connections among ideas developed throughout the unit. Each unit is made up of a series of investigations, which are in turn made up of several activities. Driving questions and overviews for each unit are included below.  

Unit 1 : Why do some things stick together, while others don’t? (7 investigations)

Students develop a model of electric interactions to explain electrostatic phenomena. To develop and revise their models, students collect evidence related to how charged objects interact with other charged or uncharged objects. They develop a particulate model of materials and a model of atomic structure to begin to build understanding of the mechanism of charging objects.  

NGSS Design Badge

Awarded: Mar 13, 2018

Awarded To: Interactions Unit 1 - Why do some clothes stick together when they come out of the dryer?



Unit 2 : How can a small spark start a huge explosion? (4 investigations)

The model of electric interactions further develops by incorporating the relationship between electric potential energy and electric forces. In particular, the unit focuses on the electrostatic attractions and energy conversions involved in the formation of molecules (chemical reactions).  

Unit 3 : What powers a hurricane? (3 investigations)

Students begin to connect the structure of molecules to explain and predict observed properties of materials. Then, students analyze and compare the energy transformations and conversions that occur during phase changes and chemical reactions. The model of electric interactions expands to incorporate permanent dipoles at the molecular level.  

Links to NGSS

The materials will help students build competency in the scientific practices defined in the Next Generation Science Standards (NGSS). The curriculum targets the following performance expectations from NGSS:
  • HS-PS3-5. Develop and use a model of two objects interacting through electric or magnetic fields to illustrate the forces between objects and the changes in energy of the objects due to the interaction.
  • HS-PS1-3. Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces between particles.
  • HS-PS3-2. Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motions of particles (objects) and energy associated with the relative positions of particles (objects).
  • HS-PS1-4 Develop a model to illustrate that the release or absorption of energy from a chemical reaction system depends upon the changes in total bond energy.

You can access the Interaction materials at A series of eight videos on “NGSS in the classroom,” featuring Kristin Mayer and the Interactions project, can be viewed on the National Science Teachers Association’s website. The Interactions materials are an open educational resource and are free for use under the Creative Commons Attribution International license (CC BY 4.0) and powered by open source software packages. When sharing this resource, please include attribution to the Concord Consortium and the CREATE for STEM Institute at MSU, and the CC-BY-4.0 license. This project was funded by the National Science Foundation (NSF DRL 1232388). Partners include the Concord Consortium and the learning Partnership USA.