A kid asked me this question just the other day, and I said that the positive part of $\ce{H2O}$ attracts the negative $\ce{Cl}$ ion and the negative part of the $\ce{H2O}$ attracts the positive Na ion.
Then he asked me several questions which stumped me:
- Why doesn't $\ce{NaCl}$ dissolve water instead (break water into $\ce{H}$ and $\ce{O}$)?
- If $\ce{H2O}$ is electrically neural, why would it attract any ions?
- Why doesn't $\ce{NaCl}$ stick together, how can one know if one molecule will attract the ions hard enough that the ions breaks away?
- Why is Na positive and $\ce{Cl}$ negative?
Hopefully someone can help me answer the above questions as I have not done chemistry in years!