Explain this statement at the molecular level!?

When substance A dissolves in substance B, basically what is happening at the molecular level is this: the molecules of substance B are getting in between and surrounding individual molecules of substance A. Two things are happening involving intermolecular forces: 1) those of substance A are being broken and 2) new bonds are forming between substance A and substance B molecules.

Now, if you have a sphere of substance A, it's going to take substance B molecules a long time to get to the center of that sphere. If substance A is a flat sheet, though, substance B molecules will be able to get to a lot more A molecules at once. In other words, the more of substance A that substance B is touching, the faster A will dissolve in B. And a greater surface area means that more of substance B will be touching more of substance A.

I hope this helps!