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 occurs in gases and with any substance in a solution. Therefore we can say that the definition of diffusion is as follows: Diffusion: The movement of particles from an area of high concentration to an area of low concentration until they spread out evenly. There are two important rules to remember. The larger the particles the slower the rate of diffusion. The greater the difference in concentration the greater the rate of diffusion. This difference is known as the concentration gradient. Example of diffusion in plant cells; Example of diffusion in animal cells