Some chemistry honors questions plz help?

Question

If i let an ice cube melt into water (assuming nothing is lost to evaporation), is there a change in mass?

What is the difference between an ice cube and water on the atomic level?

Answer 1

Yes, thanks to relativity, but it is far too small to measure, or even observe.  As a practical matter, the answer is no.  There isn't any difference between ice and water on the atomic level; only the molecular arrangements differ.