According to Graham's law, what direction does gas diffuse?

Graham's law describes the behavior of gas diffusion, stating that gases will diffuse from areas of higher concentration to areas of lower concentration. This principle is based on the kinetic theory of gases, which posits that gas molecules are in constant, random motion and will move to equalize concentration differences.

When a gas is concentrated in a specific area, the molecules have a greater likelihood of moving toward areas where there are fewer gas molecules, as they collide and interact with one another and with their environment. By doing so, the overall distribution of the gas becomes more uniform over time, demonstrating how diffusion operates to minimize concentration gradients.

Thus, the correct answer reflects this fundamental principle of gas behavior and diffusion. The other options incorrectly describe the directionality and nature of gas diffusion, failing to align with the established understanding of how gases tend to spread out in space.