Science·Matter & Materials·conceptual
Physical vs Chemical Changes
Distinguish between physical changes (reversible, no new substances formed) and chemical changes (new substances formed, often irreversible), using conservation of mass to understand both types
Suggested ages 11–13
Evidence of understanding
- Classifies given changes as physical or chemical with justification
- Explains what conservation of mass means and why mass is conserved in chemical reactions
- Names observable signs that a chemical reaction has occurred (colour change, gas produced, temperature change, precipitate)
- Explains why dissolving is a physical change but burning is a chemical change
Assessment prompt
If Physical vs Chemical Changes dissolved sugar in tea versus burnt toast in the toaster, could they explain which is a physical change and which is a chemical change — and what test would show that mass is conserved in both cases?
Standards alignment
MS-PS1-2US · ngss-ms
MS-PS1-2
Next Generation Science Standards (NGSS) Middle School
MS-PS1-5US · ngss-ms
MS-PS1-5
Next Generation Science Standards (NGSS) Middle School
KS3.Sci.Chem.AEC.4GB · uk-nc-2013
Conservation of Mass
The national curriculum in England: Key stages 1 and 2 framework document · KS3
KS3.Sci.Chem.PIS.5GB · uk-nc-2013
Physical vs Chemical Changes
The national curriculum in England: Key stages 1 and 2 framework document · KS3