Middle School Core Concepts

The following tables outline the core ideas in chemistry that should be addressed in any comprehensive middle school curriculum. Each core idea is further broken into chemical principles, and suggested concepts to teach within those ideas are listed. These tables have been generated with the guidance of the Next Generation Science Standards (NGSS) performance expectations (PEs) and disciplinary core ideas (DCIs). The task force identified the concepts that fall into each DCI within the core ideas.

The content does not need to be learned or shared in the order presented, and this is not an all-inclusive list. For example, there are PEs and DCIs within the Earth & Space Sciences (ESS) as well as the Engineering, Technology & Applications of Science (ETS) standards that could be learned by students within a physical science or chemistry course. (For example, Global Climate Change is a DCI within ESS and could easily be addressed in a physical science or chemistry curriculum.) These tables emphasize only concepts found within the Physical Science PEs in NGSS. Teachers may have additional standards (such as the Common Core State Standards in English Language Arts & Mathematics) that they need to incorporate into their teaching practice. Teachers also may need to consult state and local standards to ensure all of the essential elements and assessment boundaries of their curriculum are included.

Core Concepts of Chemistry
  • Matter and Its Interactions
  • Motion and Stability
  • Energy
  • Waves

Matter and Its Interactions

Chemical Principles (DCIs)
  • Structure and properties of matter
  • Chemical reactions
  • Definitions of energy
Chemistry Concepts
  • Chemical and physical properties
  • States of matter
  • Phase changes
  • Chemical equations
  • Evidence of a chemical change
  • Law of conservation of matter
  • Energy is involved in chemical changes

Motion and Stability: Forces and Interactions

Chemical Principles (DCIs)
  • Forces and motion
  • Types of interactions
Chemistry Concepts
  • Attractions and repulsions
  • Types of chemical bonding: ionic and covalent


Chemical Principles (DCIs)
  • Definitions of energy
  • Conservation of energy and energy transfer
  • Relationship between energy and forces
Chemistry Concepts
  • Temperature and energy
  • Convection, conduction, and radiation
  • Energy and chemical reactions
  • Chemical engineering

Waves and Their Applications in Technology for Information Transfer

Chemical Principles (DCIs)

All topics identified in this section may align more closely with physics course content.

  • Wave properties
  • Electromagnetic radiation
  • Information technologies and instrumentation
Chemistry Concepts

In a physical science course, teachers could address topics related to sound waves, light waves, and the interactions between energy and matter.

ACS Guidelines and Recommendations
for Teaching Middle and High School Chemistry

An essential resource for middle and high school physical science and chemistry teachers, curriculum developers, principals, and other school administrators who support teachers in those roles.

Learn about the nature of instruction, the core ideas to teach, the physical instructional environment, safety, sustainability, and the professional responsibilities of teachers.