Internal Energy (OCR GCSE Physics A, Combined (Gateway Science Suite)): Revision Notes
📚 Revision Notes
3.2.1 Internal Energy
Internal Energy
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Energy which is stored by particles (atoms and molecules) within a system is called Internal Energy.
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The energy takes the forms of:
- Kinetic Energy (vibration of atoms etc.)
- Potential Energy (between the particles)
Heating a System
- Heating increases the energy the particles have
- This increases the internal energy
- This either raises the temperature of the system
- Or produces a change of state Definition:
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Internal energy is the energy stored in a system by the particles. It is the total kinetic energy and potential energy of all the particles that make up a system.
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Processes:
- Melting: Solid to Liquid
- Freezing: Liquid to Solid
- Boiling: Liquid to Gas
- Condensation: Gas to Liquid
- Sublimation: Solid to Gas
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Remember in Changes of State:
- Mass is conserved
- Physical changes
- Reversible
Evaporation:
- Evaporation is when a liquid turns to a gas but only on the surface of the liquid.
- Only the particles on the surface have enough energy to turn into a gas.