Aerosols constitute an important part of the nuclei for the condensation of water droplets. In addition to absorbed gases, aerosols may also contain a substantial fraction of atmospheric component that return ultimately to the surface of the earth by wet or dry deposition. Primary atmospheric aerosols contain dust and small particles while secondary aerosols are made up of constituents of the gas phase.
With regard to acid deposition, critical loads are defined in terms of tolerable acidity deposition that must not be exceeded to avoid harmful effects. The sensitivity of a region is strongly influenced by the minerals of the bedrocks. Regions where crystalline rocks prevail are particularly sensitive.
Chelation is defined as a reaction of a metal ion with an organic molecule. Chelates are normally negative in charge and are therefore not fixed to the soil surface. The reason being that soil is negatively charged, so the soil surface typically repels the Chelates. Metals, on the other hand, are positively charged, so the positive ions of the metals are attracted to the soil surface
The equilibrium constant is defined by;
Consider a solution of 5% in 95% calcium carbonate in equilibrium with and. The composition of the suspension is as follows.