Answer:
box 4, because it has more atoms in the same amount of space
First, a physical property just identifies it's state, how it looks, color, and that stuff. Let's work on finding that.
⇔ Ability to rust wouldn't work as a physical property. That one changes the substance, making it a chemical change. So, we know that this can certainly be our answer!
True, just look at the weather channel on TV :)
DNA? I think I'm not 100% sure
