Diffusion in condensed phases, especially in natural systems such as solutions, geochemical melts and solid–solid interfaces, is an important process that remains poorly understood at a quantitative ...

Active transport is a process that moves molecules against a concentration gradient. The process requires energy. For plants to take up mineral ions, ions are moved by active transport into root hairs ...

If a crystal of a coloured soluble chemical, eg potassium manganate(VII), is placed in water, the particles spread out and mix with the water particles. As well as diffusion occurring between ...