umm how do you begin answering that ??
A) Using paper chromatography to separate pigments by density
The best answer among the choices given is option A. Chemical weathering of rocks is a source of dissolved substances in the ocean. It is a process that involves the erosion of rocks due to chemical reactions by water and substances dissolved in the water. Therefore, it most likely the source of dissolved substances.
Water is a compound that is made up of oxygen and hydrogen atoms, therefore the smallest particle of water is water molecule. The smallest particle representing water is written as H2O. H2O is the smallest unit to which water can be split while still retaining the properties of water.