Aerosol

Aerosol is atomized particles suspended in air.

According to the Dictionary of United States Army Terms, Aerosol is a colloidal system in which the dispersed phase is composed of either solid or liquid particles, and in which the dispersion medium is some gas, usually air. (There is no clear–cut upper limit to the size of particles comprising the dispersed phase in an aerosol, but as in all other colloidal systems, it is rather commonly set at 1 micrometer. Haze, most smokes, and some fogs and clouds may thus be regarded as aerosols.)