For solutes that move by simple diffusion, which of the following does NOT affect the rate of simple diffusion across a membrane?
a) the membrane pore size
b) the potential energy of the solute
c) the size of the solute
d) the concentration of the solute

a) the membrane pore size

b) the potential energy of the solute

Explanation:

Diffusion involves the random migration or movement of particles from a region of higher concentration to a region of lower concentration as a result of a concentration gradient. From the question, when particles are randomly moving across a membrane, the factors that affects migration ,  include

1. The size of the solute: Smaller sized solutes would move faster across the membrane, meaning they have a faster rate of diffusion, while larger sized solutes would move slower across the membrane, meaning they have a slow diffusion rate.

2. The concentration of the solute: When the difference in concentration of solutes across the membrane is higher, solutes will move faster across the concentration gradient ad vice versa.

the pore size of the membrane and the potential energy of the solute does not affect the rate of simple diffusion across a membrane. There is no energy expenditure in simple diffusion,