DCI in Physical Science

Table of Contents

Table 1 lists the core ideas in Physical Science, as well as the defining questions for each physical science DCI. See the framework for more examples and grade band endpoints or the NGSS website for further information.

Table 1. Disciplinary Core Ideas in Physical Science
Core Idea Defining Question

PS1:  Matter and Its Interactions

How can one explain the structure, properties, and interactions of matter?
PS1.A: Structure and Properties of Matter How do particles combine to form the variety of substances one observes?
PS1.B: Chemical Reactions How do substances combine or change (react) to make new substances? How does one characterize and explain these reactions and make predictions about them?
PS1.C: Nuclear Processes What forces hold nuclei together and mediate nuclear processes?
PS2: Motion and Stability: Forces and Interactions How can one explain and predict interactions between objects and within systems?
PS2.A: Forces and Motion How can one predict an object’s continued motion, changes in motion, or stability?
PS2.B: Types of Interactions What underlying forces explain the variety of interactions observed?
PS2.C: Stability and Instability in Physical Systems Why are some physical systems more stable than others?
PS3: Energy How is energy transferred and conserved?
PS3.A: Definitions of Energy What is energy?
PS3.B: Conservation of Energy and Energy Tranfer What is meant by conservation of energy?
How is energy transferred between objects or systems?
PS3.C: Relationship Between Energy and Forces How are forces related to energy?
PS3.D: Energy in Chemical Processes and Everyday Life How do food and fuel provide energy?
If energy is conserved, why do people say it is produced or used?
PS4: Waves and Their Applications in Technologies for Information Transfer How are waves used to transfer energy and information?
PS4.A: Wave Properties What are the characteristic properties and behaviors of waves?
PS4.B: Electromagnetic Radiation What is light?
How can one explain the varied effects that involve light?
What other forms of electromagnetic radiation are there?
PS4.C: Information Technologies and Instrumentation How are instruments that transimt and detect waves used to extend human senses?

Disciplinary Core Ideas in Physical Science

At the most basic level, systems and processes depend on physical and chemical processes. The structure and properties of matter influence the systems and processes containing that matter. Systems and processes also can be understood in terms of interactions, including forces between objects and transfers of energy. According to the framework, the overarching goal of learning the physical sciences is to identify mechanisms of cause and effect and see these mechanisms through physical and chemical principles.


In oceans, lakes, and rivers, physical properties and processes shape both non-living and living systems. For example, the structure and properties of the water molecule determine how water moves, changes state, and dissolves other substances. The interactions of wind and water masses, including the balance of forces, control how ocean currents move and how the ocean circulates. Energy is involved in the heating and cooling of water in the water cycle and in the flow of water in a river. Ocean waves serve as an excellent model for the properties of many other types of waves (see Fig. 1). Many other examples of physical and chemical processes can be found throughout aquatic science.


Image caption

Fig. 1. Ocean waves demonstrate the properties of many other types of waves.

Image copyright and source

Image by Byron Inouye


Activities and Special Features Aligned with Core Ideas in Physical Science

PS1.A: Structure and Properties of Matter

PS2.A: Forces and Motion

PS2.B: Types of Interactions

PS3.D: Energy in Chemical Processes and Everyday Life

PS4.A: Wave Properties

PS4.C: Information Technologies and Instrumentation


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Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawai?i, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.