Physical Science
MS-PS1-5
Conservation of atoms and mass
Performance expectation
Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved.
Clarification
Emphasis is on conservation of matter and physical or digital models that represent atoms.
Assessment boundary
Assessment excludes atomic masses, balancing symbolic equations, and intermolecular forces.
SEP
Practice
- Developing and Using Models
DCI
Core idea
- PS1.B
CCC
Reasoning lens
- Energy and Matter
Evidence map
Rooms connected to MS-PS1-5.
“Primary” means the chapter includes an observable performance and assessable artifact for this expectation; “supporting” builds context.
Connections recorded in the official model
ELA/literacy: RST.6–8.7
Mathematics: MP.2, MP.4, 6.RP.3
California Environmental Principles and Concepts: No direct mapping recorded.
Verified 2026-07-29. Open the official California source.