When Na+ and Cl- ions, which are bound together in a solid crystal lattice of NaCl (table salt), enter water, they undergo a process called hydration. Here's what happens:

1. Polarity: Water molecules are polar, meaning they have a slightly positive end (hydrogen atoms) and a slightly negative end (oxygen atom).

2. Attraction: The positive end of the water molecule (hydrogen) is attracted to the negatively charged Cl- ion. Similarly, the negative end of the water molecule (oxygen) is attracted to the positively charged Na+ ion.

3. Surrounding: Multiple water molecules surround each ion, forming a hydration shell. The electrostatic attraction between the ions and water molecules is strong enough to overcome the attraction between the ions in the crystal lattice.

4. Dissociation: As a result of the hydration process, the Na+ and Cl- ions become separated from each other and are surrounded by water molecules. They are now free to move independently in the solution.

Key Takeaways:

* Hydration: The process of water molecules surrounding ions is called hydration.

* Solvation: The general process of dissolving a solute (like salt) in a solvent (like water) is called solvation.

* Electrostatic attraction: The attraction between the ions and water molecules is based on electrostatic forces.

* Dissociation: The process of ions separating in solution is called dissociation.

This process of hydration and dissociation is why salt dissolves in water, making it a good electrolyte. The free ions can conduct electricity.