What is the process called when a drop of ink is added to water and the color of the whole solution changes?

The process is called diffusion. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, resulting in the uniform mixing of substances. In the case of the ink drop in water, the molecules of ink quickly move through the water, randomly colliding with other water molecules, and becoming evenly distributed throughout the solution. This results in the color of the whole solution changing.

Diffusion is a natural process that occurs due to the movement of particles in gases, liquids, and solids. It is an important process in nature, as it allows for the transport of essential nutrients and gases in living organisms. Diffusion also plays a key role in many industrial processes, such as the production of chemicals and the purification of materials.

Absorption, on the other hand, is the process by which one substance is taken up by another substance, such as a sponge soaking up water. Adsorption is a similar process, but it involves the adhesion of molecules to a surface rather than being taken up by a substance. Mixing, as the name suggests, is the process of combining two or more substances together.

In summary, the process by which the color of the whole solution changes when a drop of ink is added to water is called diffusion.