Question

which motion of particles across a membrane requires energy? from high concentration to low concentration from low concentration to high concentration with no concentration gradient through dynamic equilibrium

Explanation:

Diffusion is the movement of particles from high - to low - concentration and does not require energy. Movement from low - to high - concentration goes against the concentration gradient and requires energy input, which is called active transport. Movement with no concentration gradient or through dynamic equilibrium does not require energy for net movement.

Answer:

from low concentration to high concentration