In which scenario would the rate of diffusion of molecules be fastest?

The rate of diffusion is influenced by the concentration gradient between two regions. Molecules move from areas of higher concentration to areas of lower concentration until equilibrium is reached.

In the scenario where the internal concentration is 50 percent and the external concentration is only 12 percent, there exists a steep concentration gradient. The significant difference between the higher concentration inside the cell and the lower concentration outside creates a strong driving force for diffusion. Consequently, the molecules will move rapidly out of the cell, making this condition conducive to the fastest rate of diffusion.

This concept of concentration gradients is pivotal in understanding diffusion dynamics in biological systems. Higher gradients typically facilitate faster diffusion rates, while equal concentrations or a lesser gradient would slow down the rate significantly.