Rate of diffusion
What Rate of diffusion means in Combined Science GCSE, as defined for AQA.
Definitions of Rate of diffusion
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain Rate of diffusion in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
The number of particles crossing per unit time, which rises when a larger surface area provides more space for particles to diffuse across at the same time.
How quickly the net movement of particles from a region of higher concentration to a region of lower concentration takes place.
The number of particles that cross the membrane per unit time, which increases when the surface area of the membrane is larger.
How quickly particles cross an exchange surface, which increases when the diffusion path is short.
Topics that use Rate of diffusion
- Diffusion (AQA GCSE)
Related terms
- Adaptations of exchange surfaces
- Blood supply
- Cell size and organism size
- Concentration gradient
- Diffusion
- Diffusion and exchange surfaces
- Diffusion distance
- Exchange surface
Using Rate of diffusion in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Combined Science questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge