State changes: evaporation and sublimation
I can explain the processes of sublimation, deposition, and evaporation, and discuss the energy changes involved in these state changes.
State changes: evaporation and sublimation
I can explain the processes of sublimation, deposition, and evaporation, and discuss the energy changes involved in these state changes.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Sublimation is the change from solid to gas; deposition is the change from gas to solid, both bypass the liquid state.
- Sublimation and deposition occur at specific conditions of temperature and pressure.
- Energy changes in sublimation/deposition are similar to melting/freezing but happen directly between solid and gas.
- Evaporation is when a liquid changes to gas at the surface as particles gain enough energy to overcome forces.
Keywords
Evaporation - when a particle of a substance in the liquid state at the surface, has enough energy to change to the gas state and mix with air.
Sublimation - a change of state of a substance from a solid directly to a gas; e.g. iodine.
Deposition - when a substance changes from the gas state to the solid state without being in the liquid state.
Common misconception
Pupils think that substances need to be at their boiling point temperature to evaporate.
Use plenty of real life examples of liquids evaporating in situations where pupils know that the liquid is not above its boiling point but still evaporates.
Equipment
Microscope slides, beakers, ice, warm water/electric water baths, pipettes, propanone, stop clock.
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
Exit quiz
6 Questions
sublimation
condensation
deposition
boiling and/or evaporation
melting
freezing
when a substance in gas state is cooled and changes to liquid state
a change of state of a substance from a gas directly to a solid
if surface particle in liquid has enough energy to change to gas state
a change of state of a substance from a solid directly to a gas