Edexcel GCSE Chemistry · 1CH0
Specification 2.3 · Paper 1
- Revise: Particle Changes During Interconversions
A change between solid, liquid and gas in which the substance remains chemically the same.
Loading…
Loading…
Loading…
GCSE Chemistry · key term
A physical change between solid, liquid and gas in which the chemical identity of a substance remains unchanged.
Used by Edexcel and OCR
Specification 2.3 · Paper 1
A change between solid, liquid and gas in which the substance remains chemically the same.
Specification C1.1c, C2.3d · Paper 1 (Foundation), Paper 3 (Higher)
A physical change in which a substance changes between the solid, liquid and gas states without forming a new substance.
Do not say that particles expand or disappear during heating or a change of state. Their arrangement, movement and separation may change, but the number, identity and size of the particles remain unchanged.
For a simple molecular substance, say that intermolecular forces are overcome during a change of state. Do not say that covalent bonds within its molecules are broken.
A flat section on a heating curve does not mean that heating has stopped. Energy is still being transferred, but it is being used for the change of state rather than raising the temperature.
Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.
The basic model can represent an observed change of state by changing the arrangement and spacing of its spheres. Throughout a physical change of state, the number and identity of the represented particles must remain the same. The model also helps explain why gases are much easier to compress than solids and liquids.