Final answer:
The process of water molecules pulling solute particles into solution and forming a sphere around them is called hydration. It is a type of solvation, which specifically refers to the solvent being water. Osmosis, however, is water diffusion across membranes and is not related to the process of forming spheres around solute particles.
Step-by-step explanation:
The process that involves water molecules pulling solute particles into a solution and forming a sphere around them is known as hydration. This process occurs when a solid or liquid solute dissolves in water; the solute's particles separate and become surrounded by water molecules, which stabilize the solution and prevent the ions from recombining. This is particularly evident when compounds like sodium chloride dissolve in water, creating a sphere of hydration around each ion, such as Na+ and Cl- ions. The oxygen atom of the water molecules orients near the positively charged sodium ions, and the hydrogen atoms of the water molecules orient towards the negatively charged chloride ions, which exemplifies numerous ion-dipole interactions.
While solvation is a more general term that applies to the process of solute particles being surrounded by solvent molecules, hydration specifically refers to the situation where the solvent is water. Osmosis, on the other hand, is the diffusion of water across membranes and is not the process that refers to the formation of spheres around solute particles in solution.