A solute diffuses between two closed compartments until its concentration is equal on both sides of the permeable membrane.
Which statement describes the particles at this point?
Particles stop crossing both ways, so there is no further movement.
Particles cross both ways at equal rates, so there is no net movement.
Particles cross only towards the side that originally had less solute.
Particles cross only towards the side that originally had more solute.
42 exam-style questions on Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion, covering 8.1.1 Introduction to exchange and transport, 8.1.2 Alveoli adapted for gas exchange, 8.1.3 Factors affecting rate of diffusion, and 8.1.4 Rate of diffusion using Fick's law. Each one has a worked solution and a mark scheme showing where the marks go.