| Grade | Discipline | Core Idea |
|---|---|---|
| 6-8 | PS1.A: Structure of matter (includes PS1.C Nuclear Processes) |
The fact that matter is composed of atoms and molecules can be used to explain the properties of substances, diversity of materials, states of matter, phase changes, and conservation of matter. |
| 6-8 | PS1.B: Chemical reactions |
Reacting substances rearrange to form different molecules, but the number of atoms is conserved. Some reactions release energy and others absorb energy. |
| 9-12 | PS1.A: Structure of matter (includes PS1.C Nuclear Processes) |
The sub-atomic structural model and interactions between electric charges at the atomic scale can be used to explain the structure and interactions of matter, including chemical reactions and nuclear processes. Repeating patterns of the periodic table reflect patterns of outer electrons. A stable molecule has less energy than the same set of atoms separated; one must provide at least this energy to take the molecule apart. |
| 9-12 | PS1.B: Chemical reactions |
Chemical processes are understood in terms of collisions of molecules, rearrangement of atoms, and changes in energy as determined by properties of elements involved. |