For example, for a 12'x25' single-car driveway with a 9 bed of gravel (in three layers), convert 9 to 0.75'; multiply 0.75 x 12 x 25, which equals 8.34 cubic yards, or roughly 10-14 tons. A 4 layer of gravel to resurface an existing 12'x25' driveway requires about 2.78 cubic yards or roughly 3.33-4.73 tons.
Diffusion [edit]. Diffusion of KMnO4 in water. Diffusion is the process of a substance spreading out to evenly fill its container or environment. In a solution, a concentrated solute diffuses to spread evenly in its solvent. In air, gas molecules diffuse to mix thoroughly. Substances diffuse from areas of high concentration to low concentration.
Diffusion is the process by which substances move down a concentration gradient, from an area of high concentration to an area of low concentration. Diffusion happens in living systems, for example, it explains the movement of carbon dioxide in leaves.smosis is the movement of water from a high water concentration to a low water concentration through a partially permeable membrane. Plants absorb water from the soil by osmosis through their root hair cells.