Ground water has some minerals dissolved in it. If you heat this water, collect the vapor in another container, and then cool it, you will get pure, or distilled, water. What makes this process a physical change?
It forms a new substance (minerals), which is a physical change.
It forms a new substance (water vapor), which is a physical change.
It changes the color of water, which is a physical change.
It changes the molecular structure of water, which is a physical change.
It separates dissolved substances, which is a physical change.

Question

Ground water has some minerals dissolved in it. If you heat this water, collect the vapor in another container, and then cool it, you will get pure, or distilled, water. What makes this process a physical change?
It forms a new substance (minerals), which is a physical change.
It forms a new substance (water vapor), which is a physical change.
It changes the color of water, which is a physical change.
It changes the molecular structure of water, which is a physical change.
It separates dissolved substances, which is a physical change.

jfraser · Answer

What's the requirement for a $physical$ change instead of a $chemical$ one?