Key Stage 3
Meaning
Diffusion is when particles spread from a region of high concentration to a region of low concentration.
About Diffusion
- Diffusion can only happen in a fluid (a liquid or a gas) because the particles can move past each other.
- Diffusion cannot happen in a solid because the particles are held in fixed positions.
- In diffusion the particles always spread from a high concentration (where there are lots of the particles, to a low concentration (where there are less of the particles).
Key Stage 4
Meaning
Diffusion is when particles spread from a region of high concentration to a region of low concentration along a concentration gradient.
About Diffusion
- Diffusion can only happen in a fluid (a liquid or a gas) because the particles can move past each other.
- Diffusion cannot happen in a solid because the particles are held in fixed positions.
- In diffusion the particles always follow the concentration gradient spreading from a high concentration (where there is lots of the particles), to a low concentration (where there are less of the particles).
- Diffusion stops when all substances are spread out equally and there is no longer a concentration gradient.
References
AQA
- Diffusion pages 51-53, GCSE Biology, CGP, AQA
- Diffusion, pages 14-15, 61, 188-189, GCSE Biology; Third Edition, Oxford University Press, AQA
- Diffusion, pages 17, 20, 21, GCSE Combined Science; The Revision Guide, CGP, AQA
- Diffusion, pages 20, 21, 23-25, GCSE Biology; The Revision Guide, CGP, AQA
- Diffusion, pages 44-5, 55, 68-9, 86-7. 92, 94-5, 101, 106-7, 113, 117, 204, GCSE Biology; Student Book, Collins, AQA
- Diffusion, pages 45-47, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Diffusion, pages 5, 28, 29-33, GCSE Biology, Hodder, AQA
- Diffusion, pages 5, 29, GCSE Combined Science Trilogy 1, Hodder, AQA
- Diffusion; in other organisms, pages 31-2, GCSE Combined Science Trilogy 1, Hodder, AQA
- Diffusion; in the lungs, page 30, GCSE Combined Science Trilogy 1, Hodder, AQA
- Diffusion; influencing factors, pages 32-3, GCSE Combined Science Trilogy 1, Hodder, AQA
Edexcel
- Diffusion, factors affecting rate, page 258, GCSE Biology, CGP, Edexcel
- Diffusion, page 18, GCSE Combined Science; The Revision Guide, CGP, Edexcel
- Diffusion, page 21, GCSE Biology; The Revision Guide, CGP, Edexcel
- Diffusion, pages 20, 92-93, 112, GCSE Combined Science, Pearson Edexcel
- Diffusion, pages 24, 130-131, 162, GCSE Biology, Pearson, Edexcel
- Diffusion, pages 48, 49, GCSE Biology, CGP, Edexcel
- Diffusion; factors affecting rate, page 88, GCSE Biology; The Revision Guide, CGP, Edexcel
- Diffusion; factors affecting, pages 164-165, GCSE Biology, Pearson, Edexcel
OCR
- Diffusion, page 123, Gateway GCSE Chemistry, Oxford, OCR
- Diffusion, page 25, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
- Diffusion, pages 30, 33, Gateway GCSE Biology; The Revision Guide, CGP, OCR
- Diffusion, pages 58-59, 72-73, Gateway GCSE Biology, Oxford, OCR