Explain the rule like dissolves like more specific please. What is the contribution of the atom's structure?

Answer 1

The expression "like dissolves like" refers to polar molecules dissolving other polar molecules, and nonpolar molecules dissolving others with similar characteristics. To describe this process, electronegativity must be clarified:

Electronegativity describes an atom's attractive strength to electrons; higher electronegativity means stronger electron pull towards it. Each atom needs 8 electrons to fulfill its outer valence shell, and so the closer it gets to that number the stronger is their attraction to electrons. Flourine would be the most electronegative, and Cesium would be the least. This attraction power dictates whether it has a positive and negative dipole (like magnets). Water is a polar solvent, and oxygen (an EN atom) creates a net dipole with hydrogen that will attract other dipole molecules. When multiple water molecules surround and are attracted to its neighbors, it is effectively dissolved.

Now, oil spots and other nonpolar moles are clumped together because they don't have dipole forces.

To summarize, electronegative atoms gives molecules polarized positive and negative charges, which turns them into polar molecules. It is attacted to other molecules with the same +/- charge, and repelling away all other nonpolar molecules.