Skip to Content Go to sign in Skip to Primary Navigation Skip to Secondary Navigation Skip to Page Navigation Skip to Header Navigation Skip to Footer Navigation Read more about accessability options and our navigation

Physics Classroom is making strides to make our site accessible to everyone. Our site contains 6 navigation areas. The Primary, Secondary, and Page Level navigations have a screen reader version of their nav structure that allows using the left and right keys to navigate sibling navigation items, and up or down keys to navigate parent or child navigation items. The others can be navigated using tabs. The Primary Navigation handles the first 2 levels of site pages. The Secondary (which is not always available) handles the 3rd and 4th level of structure. The Page level navigation allows you to navigate the current page's headings quickly. The Header Navigation contains the Light/Dark Mode toggle, Search, Notifications and account login. The Breadcrumb Navigation contains the breadcrumb of the current page. If the current page has a breadcrumb, you can get to it by skipping to the content and tabbing in reverse (shift plus tab). The Footer Navigation contains links such as Privacy, Contact, about and terms. Some resources contain an Audio Player that can be activated by holding down the T key for 3 seconds, and then using K to pause and resume. While not every area of Physics Classroom is usable purely from keyboard and screen reader, we are committed to continue work on making this possible. If you have questions or need additional help, please use this link to contact us.

Return to screen reader navigation
Home Science Reasoning Crosscutting Concepts

NGSS Crosscutting Concepts

The Next Generation Science Standards (NGSS) consist of three dimensions. One of those dimensions is the Crosscutting Concept dimension (CCC). We reference these frequently in our discussion of our Science Reasoning Center activities in hopes of showing the connection between our activities and the standards. The Crosscutting Concepts listed below are from the Next Generation Science Standards website. Because our reference to the Crosscutting Concepts includes a decimal notation to refer to a specific elements of each CCC, we are listing them here with that decimal notation. This is done for clarity and convenience and is in no means an effort to make any claim of ownership or originality. The Crosscutting Concepts are the property of the NGSS.

 

 

#1 Patterns

Observed patterns in nature guide organization and classification and prompt questions about relationships and causes underlying them.

 

1.1Different patterns may be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations of phenomena.
 
1.2Empirical evidence is needed to identify patterns.
 
1.3Classifications or explanations used at one scale may fail or need revision when information from smaller or larger scales is introduced; thus requiring improved investigations and experiments.
 
1.4Patterns of performance of designed systems can be analyzed and interpreted to reengineer and improve the system.
 
1.5Mathematical representations are needed to identify some patterns.
 


 

#2 Cause and Effect

Events have causes, sometimes simple, sometimes multifaceted. Deciphering causal relationships, and the mechanisms by which they are mediated, is a major activity of science and engineering.

 

2.1Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
 
2.2Systems can be designed to cause a desired effect.
 
2.3Cause and effect relationships can be suggested and predicted for complex natural and human designed systems by examining what is known about smaller scale mechanisms within the system.
 
2.4Changes in systems may have various causes that may not have equal effects.
 


 

#3 Scale, Proportion, and Quantity

In considering phenomena, it is critical to recognize what is relevant at different size, time, and energy scales, and to recognize proportional relationships between different quantities as scales change.

 

3.1The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.
 
3.2Algebraic thinking is used to examine scientific data and predict the effect of a change in one variable on another (e.g., linear growth vs. exponential growth).
 
3.3Using the concept of orders of magnitude allows one to understand how a model at one scale relates to a model at another scale.
 
3.4Some systems can only be studied indirectly as they are too small, too large, too fast, or too slow to observe directly.
 
3.5Patterns observable at one scale may not be observable or exist at other scales.
 


 

#4 Systems and System Models

A system is an organized group of related objects or components; models can be used for understanding and predicting the behavior of systems.

 

4.1When investigating or describing a system, the boundaries and initial conditions of the system need to be defined and their inputs and outputs analyzed and described using models.
 
4.2Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales.
 
4.3Models can be used to predict the behavior of a system, but these predictions have limited precision and reliability due to the assumptions and approximations inherent in models.
 
4.4Systems can be designed to do specific tasks.
 


 

#5 Energy and Matter

Tracking energy and matter flows, into, out of, and within systems helps one understand their system’s behavior.

 

5.1In nuclear processes, atoms are not conserved, but the total number of protons plus neutrons is conserved.
 
5.2The total amount of energy and matter in closed systems is conserved.
 
5.3Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.
 
5.4Energy cannot be created or destroyed—it only moves between one place and another place, between objects and/or fields, or between systems.
 
5.5Energy drives the cycling of matter within and between systems.

 


 

#6 Structure and Function

The way an object is shaped or structured determines many of its properties and functions.

 

6.1Investigating or designing new systems or structures requires a detailed examination of the properties of different materials, the structures of different components, and connections of components to reveal its function and/or solve a problem.
 
6.2The functions and properties of natural and designed objects and systems can be inferred from their overall structure, the way their components are shaped and used, and the molecular substructures of its various materials.
 


 

#7 Stability and Change

For both designed and natural systems, conditions that affect stability and factors that control rates of change are critical elements to consider and understand.

 

7.1Much of science deals with constructing explanations of how things change and how they remain stable.
 
7.2Systems can be designed for greater or lesser stability.
 
7.3Feedback (negative or positive) can stabilize or destabilize a system.
 
7.4Change and rates of change can be quantified and modeled over very short or very long periods of time. Some system changes are irreversible.  
Return to Screen Reader Navigation